Abstract: With the increasing access of distributed resources into power network, how to quantitatively evaluate multiple connection schemes reducing its corresponding influence then becomes an urgent problem. In this paper, the maximum acceptance capacity of each power network node is obtained by an optimized model; then the voltage stability index is introduced; a normalized index is eventually given which both considers the capacity margin of distributed power and the influence on voltage stability. Finally, an example is provided to verify the specific application of the normalized index in the selection of distribution resources access scheme. The impact of distributed resources capacity and power factor on normalized index is also studied. The normalized index presented in this paper could provide quantitative data for power operation department to select the appropriate access node.