PURPOSE: To improve bending strength by sintering, in an inert gaseous atmosphere, a SiC fiber obtd. by subjecting a compd., which is formed by adding an org. metal compd. to a specific compd. and polymerizing the mixture, to a melt spinning, then to a heating treatment of infusibilization.

CONSTITUTION: An org. metal compd. such as titanium alkoxide, etc., is polymerized with an org. Si polymer compd. consisting of Si, and C as its main skeleton much as polycarbonilane to obtain the polymer compd. (A), such as polytitanocarboxysilane. The component A is subjected to the heating treatment of unfusibilization in an oxidative gaseous atmosphere of O2, etc., after the melt spinning and is then heated in the inert gaseous atmosphere of gaseous N2, etc., to obtain a SiC fiber (B) of amorphous fine grains consisting of 40 to 70wt.% Si, 20 to 40wt.% C, and 2 to 20wt.% O2. The fiber B is then heated to 1000 to 1200°C in a mixed inert gaseous atmosphere of gaseous N2, CH4, etc., to obtain a SiC fiber (C) contg. 2 to 20wt.% O2. The fiber C is sintered for 30 to 300 hours at 1400 to 2100°C and 300 to 3000kg/cm2 pressure in an inert gaseous atmosphere of Ar, etc., by which the subject SiC sintered body is produced.