Abstract: Objective To investigate the purchase and use of edible oil, as well as recycling of kitchen waste oil in Shanghai catering service units, providing reference for relevant regulatory authorities. Methods A total of 976 units of various types of catering service in Shanghai were selected via stratified sampling methodology, a self-designed questionnaire used to investigate the purchase and use of edible oil, as well as recycling of kitchen waste oil. Meanwhile, an on-site rapid detection technology was used to test items including acid value, peroxide value, polar components of unused pre-packaged edible oil and also the process of using frying oils on site. Results The amount of edible oil used in catering service units of Shanghai was about 1235 tons per day; 6.0% of the oil purchased was bulk cooking oil, which accounted for 5.6% of the total amount consumed; 44.3% of the catering service units signed with professional companies for the recycling of kitchen waste oil; 3615 samples were detected using an on-site rapid detection, of which 17 were suspected to be positive. The lab confirmed that test results were qualified. Conclusion The edible oil used in Shanghai catering service units is safe in general, while bulk cooking oil may have potential safety hazards. Food practitioners have low awareness of health risk caused by using edible oil repeatedly and for too long time, which makes some enterprise use "old oil" for too long; There does exist the possibility of kitchen waste oil returning to food chain as its recycling has not been standardized.