The negative thermal expansion and spontaneous magnetostrictive deformation of Tb2Fe15.5Cr1.5 compound have been investigated by means of x-ray diffraction and magnetization measurements. The compound Tb2Fe15.5Cr1.5 has a hexagonal Th2Ni17-type structure from 293 to 672K. A negative thermal expansion was fou nd from 432 to 522K. The coefficient of the average thermal expansion is =-157 ×10-5/K. There exists a strong and anisotropic spontaneous magnetost riction in the magnetic state of Tb2Fe15.5Cr1.5 . The spontaneous volumetric magnetostrictive deformation is about 84×10-3 at 293K and the deformation occurs mainly in the directi on of c-axis. The result of magnetization measurement shows that the Curie tempera ture of Tb2Fe15.5Cr1.5 is 494K, which is by abo ut 80K higher than the mother compound Tb2Fe17.