First, let me make a correction. In fact, GMO foods are not banned in China. The Chinese government has supported and funded many critical programs on biotech crop R&D in China. China has commercialized cultivated Bt cotton since 1997. Biotech papaya has been commercially cultivated in China since 2006. The China Ministry of Agriculture(MOA) is the major regulatory agency for biotech crops. I personally have been engaged in biotech R&D and management since 1996. I have seen MOA grant Safety Certificates for importing food and feed processing material from biotech crops including soybean, corn and canola since 2004 (see this GM Approval Database for specifics). In 2012 alone, China imported 58 million tons of biotech soybean and became the world’s biggest country for biotech soybean importation and consumption.
Individual countries and the European Union have adopted stringent regulatory processes and evaluation standards for new biotech traits prior to commercial cultivation or import as food and feed processing materials based on the biotech products assessment guidelines from Codex, the United Nations Food and Agriculture Organization, the World Health Organization and the Organization for Economic Cooperation and Development. In China, the MOA has established very comprehensive GMO safety regulations to supervise biotech crop research, development, field trials, commercial cultivation and import.
A total of 74 countries certify GM products for cultivation (growing), food import for people, feed import for animals and/or trials and testing. You can find a map of where biotech crops being grown, imported and tested here: http://gmoanswers.com/public-review.
European Commission funded-research from 130 projects involving 500 independent research groups over 25 years concluded that, “There is, as of today, no scientific evidence associating GMOs with higher risks for the environment or for food and feed safety than conventional plants and organisms.” The GMO stalemate in Europe is a political issue. The GM approval process in Europe requires a political vote after the scientific phase (safety assessment). Nine countries in Europe have introduced bans on GM crops. These bans are legally questionable under EU law (and some of them have been declared illegal by the European court of Justice) and scientifically untenable. The EU’s official food safety watchdog has consistently upheld its scientific opinions on the products affected by national bans in Europe, repeating that these products are as safe as their conventional counterparts.
GM labeling has nothing to do with food safety. It is for commercial purposes in order to distinguish GM, conventional and organic products when they are sold to consumers as they correspond to different market segments.
Further info on GM bans in EU countries: http://greenbiotech.eu/2013/08/12/national-gm-bans-scientifically-unfounded-and-legally-questionable/.