This study was designed to analyze change trends in learning-centered English class (LCEC), which is implemented in an innovation middle school and to investigate the effect of teachers’ professional development activities on the growth of LCEC. This study used the data with 938 students from the 1st to 3rd year (2012∼2014) of the Gyeonggi Education Panel Study (GEPS). A Curve-of-Factors model was employed. The findings indicated that both the initial value (level) and the rate of change of the LCEC were positive and statistically significant. Among the predictors, subject teachers conference and voluntary teacher study group activities influenced positively on the initial value of the LCEC. However, both the instructional consulting and subject study group run by local education office showed negative effects. Regarding the rate of change, instructional consulting showed increasing effects on the growth rate of the LCEC, but voluntary teacher study group activities showed a decreasing effect. In-service teacher training for curriculum showed positive, but training for teaching expertise showed a negative effect. Both teacher collaboration for teaching improvement and student guidance showed a positive effect, but collaboration for students’ class attitude and behavior showed a negative effect. Based on the results, we discussed the prevention policy for the development of LCEC and teachers’ professional development activity factors in the foreign language learning context.