Abstract: Microwave-assisted extraction（MAE）method was studied for the extraction of a natural red pigment from the pericarp of Pitaya (Hylocereus undatus Britt & Rose). Several factors, such as microwave power, extraction time and the ratio of solid to liquid were investigated, and the optimal MAE conditions were obtained from each factor and their orthogonal test. The MAE method was compared with the traditional solvent extraction for its advantages. The results showed that the optimum conditions for MAE is extracting for 80 seconds in the ratio of solid to liquid 1:3（g:ml）by microwave of 480 W with purified water as solvent. The MAE method is a fast, efficient, energy saving method, which is recommendable to the application for the extraction of natural red pigment from the pericarp of Pitaya.