Abstract: The contradiction between the complex and changeable cyberspace and the stable and harmonious real society is becoming more and more prominent， which needs relevant policy design to respond. Based on the cyberspace content governance policies issued by the National Internet Information Office since its establishment， this paper， on basis of discussing policy expression logic combined with the existing research， constructs a PMC index model to evaluate cyberspace content governance policies. The results show that there is a lack of network content identification policies. Some policies pay less attention to risk assessment， system construction and social supervision， and there are such problems as unreasonable use of tools， incomplete policy fields， insufficient policy effectiveness and so on. PMC index has strong correlations with policy tools， policy fields and policy functions， and weak correlations with policy nature and policy strategies. We should promote the optimization of cyberspace content governance policies from the aspects of improving policy effectiveness， optimizing administrative structures and innovating the application of policy tools.

Key words: cyberspace; content governance; policy expression; policy evaluation; PMC index