In this thesis, Ni 47 Mn 40 Sn 13-x ? x (x= 0, 0.5, 1, 2, 4 )ferromagnetic shape memory alloy was prepared by mechanical alloying.For making the samples, first 20g of primary material with desired stoichiometric was ball milled for 20 hours in planetary mill.Then, bulk samples were sealed in the quartz tubes under high vacuum and subjected to heat treatment at 950°C for 16 hours followed by rapid quenching in ice-water mixture.The x-ray diffraction pattern of the samples indicate that the x=0 is single phase and it has L2 1 structure. But with creating and increasing of the amount of Sn vacancy, samples will go out of single phase and don't exhibit martensitic phase. Magnetic susceptibility of all the samples indicate a magnetic transition. The martensitic transformation (MT)was observed For samples of x = 0, 0.5, but martensitic transformationtemperature of x = 0.5 is less than x = 0 and in samples x = 1, 2 and 4MT disappeared.Since in these samples (x = 1, 2, 4) lattice parameter is out of 5.98?? a ? 6.01? range, there was nomartensitic transformation. Also,the electrical resistances behavior of samples have a good agreement with susceptibility.