Abstract
We present the physics program of the open charm and heavy c states above the DD production energy threshold, which will be studied with the BES-III detector at the BEPC-II collider in the coming years. Based on some full Monte Carlo simulations with the BES-III detector, we predict the accuracy levels on measuring some physical quantities related to D0, D+ and D+s decays as well as some non-charmed decays of the heavy c states.