We have investigated the magnetic field-induced strain (MFIS) of the martensite and the parent phases in an Fe-31.2Pd(at.%) single crystal, which exhibits a martensitic transformation at T-M = 230K. Below T-M, a large MFIS of several percent appears due to rearrangement of martensite variants and this strain remains when a magnetic field is removed. Such rearrangement depends on magnetic field direction; Variants are perfectly rearranged into the variant, which lowers the magnetocrystalline anisotropy energy most, when a magnetic field is applied along [001](P), and partially when [011](P) and hardly when [111](P) ("P" represents "parent" phase). The dependence on the field direction can be explained by comparing the magnetic shear stress tau(mag) with the shear stress tau(req) required for rearrangement of variants. Above the temperature, T-M, a relatively large MFIS appears and it increases up to about 10(-3) with decreasing temperature from 280 K toward T-M. This MFIS is probably caused by anomalies of some physical properties, such as elastic constant and dipole-dipole interaction coefficient in the parent phase.