As the predominant phenolic acid, chlorogenic acid, which mainly existed in the outer layer and the peel of potatoes, was easily separated from the flesh of cooked potatoes. The decrease in the chlorogenic acid content due to cooking depends on the amount of heat used, with some methods being less effective than others. In the present study, the chlorogenic acid content was notably reduced by all of the cooking treatments. Steaming and microwaving were the least effective, whereas stir-frying, air-frying and baking were the most effective (p < 0.05). This result was in line with those reported by Dao and Friedman (1992), who demonstrated the complete destruction of chlorogenic acid during baking and a 60% reduction due to microwaving in potatoes. As an extremely unstable phenolic acid, caffeic acid was significantly affected by the cooking methods (p < 0.05), particularly those involving cooking for a long time at high temperature, such as air-frying and baking. Compared with that of the raw material, the ferulic acid content measured after steaming and microwaving was only slightly different, whereas the p-coumaric acid content after baking and steaming showed a little decrease, and boiling did not notably alter the ferulic acid content, those difference may be partly explained by the different stability of phenolic acids during cooking. In general, cooking has a negative impact on the phenolic acids, and the impact was related to the cooking methods and the kinds of phenolic acids (e.g. frying showed a more decrease than others, caffeic acid was much easier to be reduced than chlorogenic acid or other phenolic acids). In addition to the degradation during cooking, the transport from the tissue to the surrounding water and the amount that taking part in the Maillard reaction will cause a further loss of content ( de Queiroz et al., 2014).