A process for producing a silicone polymer comprising a step of subjecting, to hydrolysis and polycondensation reaction, a silane compound mixture containing 35 to 100% by mol of a silane compound represented by the general formula (I): R'.sub.m(H).sub.kSiX.sub.4-(m+k) (I) (wherein X is a hydrolysable and polycondensable group, e.g., a halogen atom (e.g., chlorine or bromine) or --OR; R is an alkyl group of 1 to 4 carbon atoms or an alkyl carbonyl group of 1 to 4 carbon atoms; R' is a non-reactive group, e.g., an alkyl group of 1 to 4 carbon atoms or an aryl group (e.g., a phenyl group); "k" is 1 or 2; "m" is 0 or 1; and "m+k" is 1 or 2), and further subjecting the resultant product to hydrosilylation reaction with a hydrosilylation agent.