Based on the research conducted, the authors proposed a new approach to the assessment of competitiveness regarding socio-economic systems. They suggest an integral index of socio-economic system competitiveness, which includes four indicators: functionality, consistency, proactiveness and wholeness of the system, as a baseline assessment of the of socio-economic system competitiveness. In order to dynamically assess the system competitiveness the authors propose to form the partial indices of competitiveness in the long-term and short-term periods.