The ad networks in China have hitherto formed their own characters in their intense competition and rapid development-led by search engines and supplemented by small and medium-sized ad networks.The sharing system greatly contributes to the development and prosperity of ad networks while mainstream media websites,portals and social networking services actively take part in ad networks so as to contend for advertising market.However,the limitation upon high-quality network flow and the chaotic market competition is jeopardizing the development of the industrial chain of advertising and is shaking advertisers' confidence in ad networks' brands.Hence related rules should be carried out for restriction and there remains a lot to be done for the ad networks in China to strengthen their self-discipline. <<