The average crude incidence was 2.01(95% CI: 1.77-2.28) and 0.76(95% CI: 0.61-0.93) for T1DM and T2DM, respectively. There was a significant increasing trend in the incidence of T1DM during the period of 2001 and 2010, with an annual 1.08-fold increase of the rate ratio (95% CI: 1.03-1.12). The trend in the incidence of T2DM increased with an annual 1.23-fold increase of the rate ratio (95% CI: 1.14-1.33). The incidence of T2DM among those aged 10-14 years was rapidly increased during the period of 2001 to 2010 and was higher than that of T1DM in 2010. The rate ratio for development of T1DM was 1.16-fold higher in males than females and that for those aged 1014 years was a 2.04-fold higher when compared to those aged 0-4 years. Also, there was an 1.43 increased rate ratio in Busan (urban) compared to Gyeonnam province (suburban). The rate ratio for development of T2DM was 1.29-fold higher in males than females and that for those aged 10-14 years was a 9.59-fold higher when compared to those aged 5-9 years. Also, there was an 1.58 increased rate ratio in Busan (urban) compared to Gyeonnam province(suburban). Conclusions The incidence of T1DM and T2DM have shown a significant increasing trend for last 10 years in Busan and Gyeonnam province, Korea. Our study shows the needs for careful monitoring of incidence and its related risk factors of T2DM in adolescents.