We report the fabrication and photocarrier dynamics in graphene-MoSe2 heterostructures.The samples were fabricated by mechanical exfoliation and manual stacking techniques.Ultrafast laser measurements were performed on the heterostructure and MoSe2 monolayer samples.By comparing the results,we conclude that photocarriers injected in MoSe2 of the heterostructure transfer to graphene on an ultrafast time scale.The carriers in graphene alter the optical absorption coefficient of MoSe2.These results illustrate the potential applications of this material in optoelectronic devices.