Objective: In uncontrolled type 2 DM patient, when combination insulin treatment swich to OAD only , we want to know difference of level of BMI and HbA1c at initiating insulin Tx and changing and stopping insulin treatment. Methods: We enrolled 616 person who used insulin in 2012. January ~2015. May. We included 142 person (M:74, F:68) and excluded 474 person due to follow up loss, continued insulin combined Tx, etc. Results: Median of insulin using period was 5 months. Patient's characters when initial conbined treatment age: 58 ± 15.3 BMI : 24.5 ± 4.21 kg/m² HbA1c: 11.1 ± 2.39%. Conclusion: In our data, When HbA1c becomes 7.3 ± 1.52%, we could conduct OAD changing. When we did OAD changing, 0.18 kg/m² BMI defference was producted, and the difference was not significant. From now, we believed that insulin treatment cause weight gain. But in this study, that concept and result was different.