In order to improve the tribological properties of Ni-based composite coatings, the composite coatings were prepared by atmospheric plasma spraying and heat treated at at 400 oC,500 oC and 600 oC, respectively. The influence of heat treatments on the microstructure, microhardness, adhesive strength, high temperature oxidation resistance and tribological properties from 25 oC to 900 oC of NiCrAlY-Mo-Ag composite coatings were investigated. The results show that the microstructure of the coating becomes more homogeneous and more precipitated phase of Y2O3 arises after 500 oC heat treatment. The precipitated phase dispersively distributes in the matrix which could work as the oxide dispersive strengthening phase in the composite coating. Meanwhile, the heat treatment could also improve the micohardness of the composite coatings. The adhesive strength between composite coating and substrate enhanced by heat treatment and that coating heat treated at 500 oC registered the highest adhesive strength of 42.90 MPa. The composite coating heat-treated at 500 oC possess the excellent lubricating properties at all test temperatures. The tribo-chemical reaction between silver and molybden m occurs and the silver molybdate lubricating film forms on the worn surface at 700 oC and 900 oC. At the same time, the composite coating heat treated at 500 oC shows the excellent high temperature oxidation resistance.