|In this study, the researcher developed a real-time PCR-based assay using SYBR-green dye for the detection of contaminated meat in vegetarian foods. The highly efficient real-time PCR assay was able to distinguish between meat and plant foods using an amplified 161-bp 18S rRNA gene (1st primer pair). The difference in Tm (melting temperature) of substances of animal and plant origin was revealed at 82.15-82.75°C and 80.36-80.50°C, respectively. In addition to this, the 28S rRNA gene was used to confirm the result in that contaminated meat (fish, crab, pork and beef) can be indicated. This validate real-time method was specifically identified chicken contamination using another part of 18S rRNA gene (2nd primer pair). The developed assay was also applied to examine 24 products labeled vegetarian food obtained from local supermarkets and 16 out of 24 (66.67%) were contaminated with meat. Evaluation of the assay sensitivity demonstrated a 0.001% of the chicken DNA substitution of soybean DNA can be detected.