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Materials with negative thermal expansion have many practical applications.However,these materials are known in only several oxide systems,and when the negative thermal expansion occurs,the contraction is usually small and limited to a narrow temperature range beyond room temperature.For obtaining a compound with negative thermal expansion in broad temperature range,the structural and magnetic properties of Gd2Fe17 compound were investigated by means of X-ray diffraction and magnetization measurements.The Gd2Fe17 compound annealed at 1050 ℃ had a Th2Zn17-type Structure.There existed an anisotropic strong spontaneous magnetostriction and a negative thermal expansion in Gd2Fe17 compound.The average thermal expansion coefficients was α =-7.40×10-6/K in the temperature range of 294-453 K and (α) =-1.80x 10-5/K in 453-534 K,respectively.The spontaneous rnagnetostrictive deformation ωs decreased from 4.34x10-3 to near zero with temperature increasing from 294 to 572 K.The spontaneous linear deformation λc was much larger than λa at the same temperature below about 500 K.