Neutron diffraction studies were made on amorphous silicon hydrides α-SiH0.39 and α-SiH0.14 The reduced radial distribution functions(G(r)) were obtained. For both, samples, the third and the fourth G(r) peaks were found to be at 3. 89 A and 5. 79 A respectively. Upon partial dehydrogenation of α-SiH0.39 at 350℃, the second G(r) peak (2. 52(?)) split up into two subpeaks (2. 08(?) and 2. 56(?) ) , indicating that Si=Si double bonds might have formed. These results were thought to be important for understanding hydrogen evolution mechanism of amorphous silicon hydrides. Neutron diffraction studies were made on amorphous silicon hydrides α-SiH0.39 and α-SiH0.14 The reduced radial distribution functions (G (r)) were obtained. For both, samples, the third and fourth fourth G (r) peaks were found to be at 3. 89 A and 5. 79 A respectively. Upon partial dehydrogenation of α-SiH 0.39 at 350 ° C, the second G (r) peak (2. 52 (?)) split up into two subpeaks 08 (?) And 2. 56 (?)), Indicating that Si = Si double bonds might have formed. These results were thought to be important for understanding hydrogen evolution mechanism of amorphous silicon hydrides.