We investigate the effect of doping on FeCoZrGe. Electronic structure calculations reveal that doping of As or Nb into FeCoZrGe will transform it into half-metallic materials. They have half-metallic properties in a large range of proportion of As or Nb's doping. So by doping with different proportion of As or Nb, the controllable half-metallic gaps can be realized. In addition, this doped system can have higher Curie temperature.