The Pb and Cd contents in 12 kinds of cereal samples were determined by microwave digestion -graphite furnace atomic absorption spectrometry, respectively. The pollution situations of the samples were assessed according to the national safety standards about the pollutant in cereal. The dietary exposure risk of Pb and Cd in cereal was assessed according to the maximum allowable intake of heavy metal pollutants （RfD value）recommended by USEPA (2000). The results showed that the exposure risk coefficient of Pb and Cd was less than 1 with the dietary patterns of eating single rice or two kinds of grain collocation. But all samples were slightly contaminated by Pb; maize, oat and wheat flour were slightly contaminated by Cd; while rice, pea, broad bean were around the warning line of Cd pollution. It is necessary to reinforce supervision of heavy metal pollution in agricultural products market.