The present invention relates to a pharmaceutical composition for treating diabetes, containing metformin and a DPP-TV inhibitor. The pharmaceutical composition for treating diabetes according to the present invention can cut off the contact between the DPP-TV inhibitor and metformin, so that the lifespan of the composition is increased and the amount as well as the kind of a flexible material contained in the composition is reduced. Furthermore, the DPP-TV inhibitor can be rapidly released and the sustained-release of metformin can be controlled.
