Based on the principle of result oriented，Public view and Policy oriented，the index system of assessing online information disclosure of county government portals was constructed. The quantitative evaluation on the Online Information Disclosure of 108 county government portals was made according to the index system. Results show that WUGANG county，QI XIAN county，GONGYI city，ANYANNG Xian county，rank among the top five in Henan Province. The average score on the Online Information Disclosure of county government portals among Henan Province is 51.6，and which are great differences among counties. The amount of online information disclosure is much，but timeliness and explicit are weak. The level of online information disclosure is influenced by Per capita public finance income and urbanization rate，the direct leader from prefecture level municipal government is more significant.