Butene-1 production through a selective ethylene dimerization is one of the largest industrial processes, which is catalyzed by homogeneous catalyst system. The common industrial catalyst system is comprised of Ti alkoxide-based catalysts in combination with AlEt3 as an activator. In this study, the alkylsilanes were used as novel improving agents in the catalyst system for highly selective ethylene dimerization to butene-1. The nature and concentration of alkylsilanes on the dimerization rate, catalyst yield, by-product production, and selectivity to butene-1 were investigated in detail. It was found that alkylsilanes improved the productivity and selectivity of the catalyst. Moreover, the content of the solid by-product considerably decreased. The performance of the modified catalyst system was noticeably higher than that of the nonmodified one. Totally, it was proved that alkylsilanes could play a modifying role in the selective ethylene catalytic dimerization process.