Abstract: The structure and properties of electroless Ni-P amorphous alloy under the simulated welding condition by changing the temperature and time of heat treatment were investigated.It has been shown that the crystallization of Ni-P alloy would not accur when time of heat treatment is shorter than 60 seconds.(beside 1000℃,60s),but the hardness of the alloy increases obviously.Under the condition of heat treament with shorter time,the handness of the alloy reaches the maximum when the temperature of heat treatment is 700℃.