Abstract: The establishment of the maximal residue level(MRLs)of pesticide and implementation of national enforcement system are necessary for guiding the good agricultural practice(GAP), and protecting the human health. In this paper, the principles and guidances from Organization for Economic Co-operation and Development(OECD) and other countries were reviewed, including the composition, classification and purpose of pesticide residue definition. Furthermore, the progress on pesticide residue definition in China was described. And suggestions were given for the development of pesticide residue definition and market residue survey in China.