The magnetic properties of NdFeBand NdFe(61-x))CoGaB(x=0,1,2,4,7)have been measured.Itis found that the remanent magnetization(Br),maximum energy product(BH)and the Curie temperature(T)decrease with the increase of Ga content.The coercive force(He)increases with the increase of Ga contentwhen x is less than 2,but decreases when x>2.At x=2,the coercive force reaches its maximum value.It is alsofound in all the samples investigated that there is a linear relationship between Hand T,which can not beexplained by Gaunt’s wall barrier model.The temperature dependence of the calculated values of Hand(4bf)has been discussed.