Abstract: A number of researchers have argued that teacher behavior is a powerful predictor of student achievement.The topic of the relationship between teacher's instructional behavior in classroom and student achievement is revisited in an international setting using the Trends in International Mathematics and Science Study (TIMSS) 2003 data,which is analyzed using Hierarchical Linear Model (HLM).The results from USA,Sweden,Japan and Hong Kong show that: (1) Instructional behaviors,like teacher's preparation to teach,teacher's emphasis on mathematic homework,teacher's emphasis on test,teacher's emphasis on reasoning and problem resolving and the use of computers in math class,do have significant positive impact on achievement scores in USA and Sweden,but have no impact in Japan and Hong Kong.(2) In general,teacher's certification variables,including sex,teaching experience,level of education,major and teacher quality,have no significant effect on achievement scores in any countries.(3) The factors of family background and student's own characteristics,such as age,sex,time students spending doing mathematics homework,students' self-confidence in learning mathematics and students' evaluation of mathematics,still have an important effect on student achievement.

Key words: teacher, instructional behavior, students achievement, TIMSS2003