Abstract: The epoxy bonded Sm_1-xD_yxFe₂ composites were prepared. The magnetostriction, dynamic magnetostrictive coefficient and coupling coefficient of the epoxy bonded composites were measured and the magnetic field dependence of magnetostrictive properties was investigated. It is found that the magnetostriction of epoxy bonded Sm_1-xDy_xFe₂ composites increases with increasing x in low magnetic fields, but it goes the opposite way in high magnetic fields. The magnetostriction of Sm_{0. 88}Dy_0.12Fe₂ rod sample is 405 x 10^-6 at the field of 200 kA/m. The maximum values of magneto-mechanical coupling coefficient and dynamic magnetostrictive coefficient are 0.34 and 1.28nm/A, respectively. Therefore, epoxy bonded Sm_0.88Dy_0.12Fe₂ composite is a valuable material for practical application.