The controversy of genetically modified（GM）food safety continues to ferment，and the popularity of public opinion is rising，GMG becomes one of the hottest topics in the world. In order to guide mainland Chinese public have a rational opinion on safety of GM food，this paper analyze the developmentof GM food safety since 2001，and clarify the formation mechanism of public behavior and attitude to GM food safety from the perspective of network public opinion in the mainland. The study found that public pays more attention to GM food which belongs to grain crops，which is also the most problematic category of GM food safety in mainland China. Meanwhile，the result showed that the network public opinion on GM food safety has experienced five stages during 2007-2013 in China，including the embryonic stage，the burst phase，the spreading stage，the blowout phase，and the stationary phase. In addition，the transmission path of network public opinion on GM food safety was constructed through analyzing the specific incidents and constituent elements in the blowout phase，the network public opinion on GM food has the typical characteristic of mass communication-group communication，media and internet users have obvious negative attitude to GM food，it is not conducive to the objective propagation of public opinion on GM food safety in China mainland. Therefore，government should regulate the network public opinion on GMF safety positively，guide the public behavior and attitude of GM food safety scientifically，and create a fair environment for the development of GM technology and GM food.