Objective To discover the food contamination of lead, cadmium and mercury and provide basic evidence for the risk assessment. Methods According to the surveillance plan during 2012-2016, samples were collected from 12 regions of Inner Mongolia separately. The lead, cadmium and mercury content in food was measured and evaluated according to the national standards. Results Eight kinds of food were monitored during 2012-2016. 4 212 samples were tested for lead. The detection rate was 32.72% (1 378/4 212), and the violation rate was 0.76%(32/4 212). The violation rate was the highest in mushroom, wtih 7.37%(14/190). 4 173 samples were tested for cadmium, the detection rate was 54.18%(2 261/4 173), and the violation rate was 0.58% (24/4 173). The most violations were in mushroom, aquatic products, meat and meat products, with the violation rate of 3.68%(7/190), 2.06%(9/437) and 1.15%(6/524) respectively. 4 217 samples were tested for mercury. The total detection rate was 32.68%(1 378/4 217), total violation rate was 0.50%(21/4 217), the most violation were in mushroom and vegetables. The violation rate was 3.68%(7/190) and 1.01% (11/1 088). Conclusion The evidence showed that mushroom, aquatic products, meat and meat products, vegetables were contaminated by heavy metal in Inner Mongolia.