Thermal expansion behaviors of variously heat treated CuZnAl shape memory alloy （SMA） were measured by thermalilatometry and differential scanning calorimetry （DSC）.It was revealed that heat treated CuZnAl shape memory alloy not only possesses different shape memory effects but also exhibits various thermal expansion behavior at different temperatures.During the martensitic reversible transformation

the peak value of the coefficient of thermal expansion （CTE） of CuZnAl occurs

and the CTE of CuZnAl SMA by water quenching is higher than that of by step quenching.After phase transformation

the CTE of CuZnAl SMA by step quenching is lower than that of by water quenching ranging from 80 to 240 ℃.The CTE is decreased with the increase of temperature in the temperature ranges either water quenching or step quenching.Also the peak of the CTE occurs ranging from ranges of 240 to 280 ℃ due to the existence of a few of bainite phase.Therefore

both the methods of quenching and the ageing time can influence the CTE in CuZnAl SMA.