Abstract: NdFeB permanent alloy exhibits very high magnetic properties, but its application scope has been limited for its low curie temperature(about 310℃) and high temperature coefficient(remanence reversible temperature coefficient is about -0.13%/℃ in a temperature range of 20-100℃). In this study, curie temperature was raised and temperature coefficient was reduced by adding Co and other trace elements. As the temperature stability has been improved the high magnetic properties are still kept. The optimum properties of the samples obtained are as follows:Br=1.29T, iHc=648kA/m, bHc=584kA/m, BH_max=304kJ/m_3, Tc=500℃, α_Br=-0.05%/℃.