The research is aimed at determining tendencies to change the proportion of economic elements and at defining basic funds marginal efficiency in key industries of agricultural enterprises in the regional agro-industrial complex. The research shows the theoretical theses that present natural, structural and economic conditions affecting the reproduction structure and tempo of basic production assets. The author determines factors affecting real capital productivity. He also identifies marginal efficiency of basic funds in intensive and extensive sectors in agricultural enterprises of agro-industrial complex in Komi republic. It is defined that fluctuation types of basic funds marginal efficiency index are different in sectors. Pendulous fluctuation is typical for intensive sector whereas extensive sectors are characterized by randomized cyclic fluctuation interspaced in time. Research results can be used while developing sector economic plans in the regional agro-industrial complex.