For fine control of operating temperature of shape memory alloy, we investigated the effect of thermal teratment of shape memory alloy with the impurity kind. The martensitic transformation temperature in a Cu-17.25Zn-15Al and Cu-17.25Zn-15Al-1Ag/Fe was measured using electrical resistivity as a function of quenching temperature. Order-disorder phase transition temperatures in parent phase were measured and kind of transition were distinguised by DSC(differential scanning calorimeter) with heating rate variation. And structual changes were studied with XRD. For the Cu-17.25Zn-15Al shape memory alloy, the order-disorder phase transition temperature, $T_{B2}$ and $T_{L21}$ was 809K and 610K and for the Cu-17.25Zn-15Al-1Ag and Cu-17.25Zn-15Al-1Fe specimen $T_{B2}$ and $T_{L21}$ was 794K and 610K, and 803K and 613K, respectively. In all the specimens, quenching from near $T_{B2}$ leads to an increase in martensitic temperature, whereas quenching from near $T_{L21}$ leads to an decrease in martensitic temperature.