【正文】 . The Relationship with Linguistics 4. The Relationship with Psychology 5. The Relationship with Psycholinguistics 5. Second Language Acquisition Significance of the Study 53. Major Individual Factors in Second Language Acquisition 6. Physiological Factors 7. Different Views on the Factor of Age 7. The Research Results of Age Factor 9. Cognitive factors 10. Intelligence 10. Language Aptitude 11. Learning Strategies and Communication Strategies 12. Emotional Factors 13. Motivation 14. Personality 154. Conclusion 16Works Cited 18 On Individual Factors in Second Language Acquisition Research1. IntroductionFor a longtime, foreign language research usually focuses on the different approaches of teaching. And in this respect, much has been achieved. And these teaching theories had really contributed grossly to our different probes to the alleged best way in FLT or SLT. Language is a munication tool, but it is also the basic of cultures and development. Communication needs people to master a second language other than their mother tongue or even a third language, which is resulted from social development. Language acquisition in terms of psychological or social process is indeed a very plicated process. Therefore, theoretical research on language acquisition has also been continuously carried out. Second Language Acquisition formally established itself as a discipline around the 1970s, refers to the systematic study of how one person acquires a second language subsequent to his native language. Second language acquisition, is the processes by which people learn languages in addition to their native tongues. Just as second language is the standard term for any language whose acquisition starts after early childhood,However, there are really some facts we have to face. The Individual Difference Factors research is still in its primary stage nowadays. After years of research, scholars have reached a consensus about the most important ponents of the individual factors. Second Language Acquisition mainly studies second language acquisition process, and various factors in the process such as learning motivation, learning strategies, learning style, learner’s personality and learner’s age, and the impact of second language acquisition. In this paper the most important and the most frequently mentioned elements are: age, intelligence, language attitude, learning strategies, munication strategies, motivation, attitude, personality, inward and outward, selfesteem, inhibition, anxiety, and empathy. This paper is to argue for the necessity of considering different individual factors. The teacher’s task is to understand all the differences and to take advantage of them. It is believed that the efficiency of language teaching and learning in China can be greatly enhanced, so long as we pay attention to learner factors in the teaching process.2. Second Language Acquisition ResearchLanguage acquisition is concerned with language development in humans. In general, language acquisition refers to children’s development of their first language, that is, the native language of the munity in which a child has been brought up. The development of a first or native language (L1) is called first language acquisition (FLA), and then second language acquisition (SLA). L1 and L2 development do not seem to involve identical processes. Whether you are learning a language naturally as a result of living in a country where it is spoken, or speak generically of second language acquisition (Ellis， 2000). Second language acquisition, or sequential language acquisition, is learning a second language after a first language is already established. Many times this happens when a child who speaks a language other than English goes to school for the first time. Children have an easier time learning a second language, but anyone can do it at any age. It takes a lot of practice!s language system. In other words, second language learners have their own language system. The language system is neither the mother language system nor the target language system. And the second language acquisition researchers are concerned with the rule system of the learner’s language.. Second Language AcquisitionThe Relationship between the Relevant Disciplines. The Relationship with LinguisticsLinguists regard the native speaker’s language system as its object of research。 on second language acquisition have a definite impact on physical, cognitive, emotional and other characteristics, individual difference is an objective of the individual factors, individual factors involves learning style, learning strategies and affective variables, these factors largely affect second language acquisition. Individual differences main include such factors as age, sex, personality factors, language learning strategies, cognitive and emotional factors, motivation, attitude and so on (Altman1980,Skehan1989). Therefore, this approach has been widely used in study methods of individual differences (施家煒, 2003).. Physiological FactorsThe main physiological factor of second language acquisition is age. Age in Second Language Acquisition is an issue that has not been well resolved, and there is still a very plex controversy on it. However, the key period to learn a second language means learning a second language at the best age. Many scholars also believe that it is the period before the beginning of puberty. In that period children can learn a second language easily and are more likely to succeed, especially in the voice and speaking. After this critical period, learners may experience more difficulties and are less likely to achieve a native like accent. This shows that adult second language learners are difficult to achieve high language proficiency. But at the same time, many people object to that statement. Many scholars also believe children39。aptitude1