Abstract: In order to make the results more intuitive and reduce the uncertainty caused by shortage of data,this study was designed to verify that Boston Matrix could be used for semi- quantitative risk assessment.Boston Matrix was used to evaluate Listeria monocytogenes risk in chilled sausage.The actual detection rate based on test results was calculated,then the β distribution was defined by @ Risk software,and the probability of 95% confidence interval was used as a possible detection rate. Moreover,the risk matrix based on Boston Matrix theory was established for L. monocytogenes in chilled sausage. Results indicated that the risk order of each test sample contaminated by L. monocytogenes was as follows: raw materials > intermediate products > raw environmental district > cooked environmental.In conclusion,this method proved to be fit for semi- quantitative risk assessment,and might be decision- making reference for risk managers.