To improve the magnetic and mechanical properties of a Heusler alloy ofNi52Mn24Ga24, iron was doped with some contents. Singlecrystals of the pseudoquaternary Heusler alloy ofNi52Mn9Fe15Ga24 have been synthesized for mechanicaland magnetostrictive measurements. The magnetostriction loops andstress-strain curves were measured under different coupledmagnetic-mechanical loads. The experimental results show that thebrittleness of the sample is clearly improved and Young'smodulus of 13.7 GPa is obtained in the [001] direction due to the partsubstitution of Fe for Mn. Furthermore, the toughness andVickers hardness of the sample are also given by use of the indentationtechnique.