This study was carried out to examine the mutagenicity of extracts from grilled pork belly and the effect of garlic on it by using Arnes test. And in order to imitate the in vivo metabolic activation system of the mutagens, the enzymatic activation system was adopted. The results are summarlized as follows: 1. The degree of browning in pork belly extracts increased with the increasing heating intensity of the grilling. 2. When pork belly grilled at "low" heating intensity, no mutagenicity was detected. However with the samples grilled at "medium" and "high" heating intersity, mutagenicity was recognized. 3. The mutagenicity of grilled pork belly extract decreased remarkabley with the addition of S-9 mix. 4. The mutagenicity of grilled pork belly extract decreased with the addition of garlic extract.