Hot rolled 00Cr40Ni55A13Ti alloy was studied and 1150-1250 ℃ solution treatment+air cooling/water quenching process was conducted on the tested alloy in order to find out the influence of solution temperature and cooling method on microstructure and mechanical properties of the 00Cr40Ni55Al3Ti alloy.The results show that the size of grain and α-Cr phase increases with the increase of solution temperature in the range of 1150-1250 ℃,and the grain size grows rapidly when the solution temperature is over 1150 ℃.When the alloy is solution treated over 1200 ℃ followed by air cooling,α-Cr phase precipitates in a layered pattern at the grain boundary.The microhardness of the alloy decreases with the solution temperature increasing,and the impact absorbed energy peaks at 1200 ℃.When the water cooling is conducted,there is an inhibition in the precipitation of α-Cr phase and nano-sized y'particles,consequently,the hardness and impact absorbed energy decreases and increases,respectively,compared with air cooling.Tensile properties are strongly influenced by the cooling method,the tensile strength is relatively higher under air cooling.And there is a 26.5%decrease in the elongation when solution treated at 1250 ℃ followed by air cooling,due to the mixed grain and coarse layered microstructure at grain boundary.