The pore radius of the silica glass prepared from a borosilicate glass could be controlled by the content of alumina in the starting glass in the range from 1.9 nm (0 wt% alumina) to 1.9 nm (4.5 wt%). The hydrogenation of three kinds of 1-hexenes and 1-octenes, respectively, was carried out over nickel catalysts supported on a series of the porous glasses different in pore size to elucidate the effects of pore size on the rates of hydrogenation. The rates over the catalyst with the largest pore radius (1.9 nm) were almost the same among the 1-hexenes and 1-octenes, respectively. As the pore radius decreased, however, there was observed an increasing tendency that the rates of branched (or more spherical) olefins such as 3,3-dimethyl-1-butene and 2,4,4,-trimethyl-1-pentene far exceeded than those of the corresponding linear olefins, i.e. 1-hexene and 1-octene, respectively. This shape selective behavior is quite different from that of the zeolite-supported catalyst. These results confirm that a catalyst support with unique shape selectivity can be synthesized from the borosilicate glass with a small amount of alumina.