Since the 1970s, genetically modified (GM) technology has developed rapidly and GM foods have been increasingly appearing in our daily lives. To address the safety issues of GM foods, since the 1990s, countries and regions have introduced laws and regulations on GM foods. For example, in the United States (U.S.), the federal GM food law adopts the principle of substantial equivalence and uses a product-based standard to evaluate the safety of GM foods. The European Union (EU), however, advocates process-based legislation and adopts the precautionary principle as the regulatory principle. More recently, with the emergence of the gene editing technology, the market of gene-edited foods has raised heated debates about how to efficiently regulate gene-edited foods. This thesis, by using literature review, case study, and comparative legal study methods explored the history and characteristics of the EU law on GMOs, analyzed the problems of the EU law on GMOs and their adverse impacts on the progress of EU GM technological research. Furthermore, this study examined regulatory challenges associated with gene editing technology to the EU GM food law. By comparing the definition of GMOs with gene editing and analyzing the judgement of ECJ case 528/16, the study argued that foods using gene editing technology do not fall within the scope of the EU law on GMOs, and that gene editing foods should be regulated under the current EU food safety regulatory framework rather than GMO laws. By the end, the study proposed several recommendations for the improvement of EU law on GM foods. Key words European Union law; Genetically modified organisms; Rigorous; Gene editing; Precautionary principle; Substantial equivalence;