Total diet study (TDS) is designed to collect concentration data of chemicals in foods analysed as consumed by the population living in a country and, if possible and where relevant, population subgroups. The WHO strongly recommends the member countries to carry out TDS and the TDS data are used to assess the chronic dietary exposure as the most economic, reliable and effective tool. China has put TDS as groundwork for the risk assessment and standard setup action plan. The comment briefly introduces the TDS background, evolution from start, development and maturity in the past 30 years. And also, it comments TDS in the position of exposure science in food safety.