To evaluate the voltage and reactive power operating status of the regional power grid in the sight of harmony, and give the quantified reason for the operating status not good, an evaluation index system for voltage and reactive power operating status of regional power grid under automatic voltage control (AVC) is proposed. According to the power system measured data, the index system is indicated based on the voltage and reactive power evaluation criteria and AVC control strategy of the regional power grid. The proposed index system includes area power supply bus voltage qualification degree and disqualification reason evaluation index, area gateway reactive power qualification degree and disqualification reason evaluation index, area load reactive power balance level and unbalance reason evaluation index. To verify the rationality and validity of the proposed index system, the evaluation analysis results of the power grid in Shantou of Guangdong Province are given. The assessment results can give some suggestions on the AVC operation parameter set, control strategy optimization, and reactive power compensation planning of the regional power grid.