This report describes the assessment framework，data collection and analysis methods，and indicator calculation method of China Open Public Data Provincial Index. The report evaluates 27 provinces in the country except Hong Kong，Macao，Taiwan and municipalities directly under the Central Government，and gives suggestions for future development. The report shows that up to October 2021，193 provincial and city governments in China have open data platforms in service，including 20 provincial platforms（including provinces and autonomous regions，excluding municipalities and Hong Kong，Macao and Taiwan）. The number of provincial platforms has increased year by year，showing a trend of continuous expansion from southeast to the central and western regions. Zhejiang and Shandong provinces performed best overall. In the four key dimensions，Zhejiang Province ranks first in Readiness，Platform and Data dimension，and Shandong Province ranks first in Use dimension. The report uses a four-year cumulative score of “ODympic” to reflect a place’s continuous level of open data in the past four years（2018-2021），and finds that Zhejiang Province has the highest score，followed by Shandong Province，Guizhou Province. and Guangdong Province. The report further shows the provincial benchmarks in four key dimensions：Readiness，Platform，Data and Use，and put forward a series of suggestions from the aspects of institutional supply and organization support，platform improvement and sustainable operation，data quantity enhancement and quality assurance，data use and ecology cultivation.