The structural and magnetic properties of Sm2Fe17-xCrx compound have been investigated by means of x-ray diffraction and magnetization measurements. The results show that the Sm2Fe17-xCrx （x=1—3） compounds annealed at 1050 ℃ for 5 days have a rhomhedral Th2Zn17-type structure，and the Sm2Fe17-xCrx（x=25, 30） compounds annealed at 1050 ℃ for 7 days have a monoclinic Nd3（Fe，Ti）29-type structure. Long annealing time and high content of Cr can make the Sm-Fe-Cr compound with a Nd3（Fe，Ti）29-type structure become very stable. This is quiet different from the R2Fe17-xCrx compound （R is a heavy rare earth element）. The analysis of unit-cell volume and unit-cell parameters show that there exists a strong anisotropic magneto-volume effect in Sm2Fe17-xCrx compounds. The result of magnetization measurement shows that the effects of the substituting Cr for Fe at dumbbell sites on the Curie temperature and the magneto-crystalline anisotropy of the compound with Th2Ni17-type structure are greater than that of the compound with Th2Zn17-type structure.