International requirements on location and number of supervised residue trials for pesticide registration

In the supervised residue trials for pesticide registration,it was essential to have enough trials and the representative locations.The principles and guidelines for the trial number and location selection of the trials issued by Food and Agriculture Organization (FAO),Organization for Economic Co-operation and Development (OECD) and Environmental Protection Agency (EPA)(USA) were reviewed.Meanwhile,the comments were put up based on the current conditions of crop regions in China.It was helpful to give the guidance of trial number and location selection of the supervised residue trials in China.