We have investigated the magnetic properties and magnetostriction of ZnxNi1-xMnSb compounds prepared by solid state reaction method. It is found that for x less than 0.6 the magnetization of ZnxNi1-xMnSb almost remains unchanged. However, when x is larger than 0.6 the magnetization starts to drop linearly. Experimental result indicates that at low Zn concentrations, x < 0.7, the Curie temperature (TC) decreases with increasing Zn concentration x. However, when x > 0.7, the Curie temperature increases distinctly with increasing x. The Zn concentrartion dependence of magnetostrictive ceofficient is also studied. The experimental curve shows that when x < 0.6 the value of magnetostriction coefficient for ZnxNi1-xMnSb decreases linearly with the increasing Zn concentration x. However, when x is above 0.6, the magnetostrictive ceofficient raises distinctly. By analyzing the XRD pattern, the structures of the materials are examined and the relationship between the properties and the structures are discussed. A structural phase transition is observed. It has been indicated that the structure plays an important role in the magnetic and magnetostrictive properties of the system.