Abstract: The objectives of this study were to develop an optimized method for removing cadmium from Pyropia haitanensis and to evaluate the nutritional value. Response surface methodology ( RSM) based on a Box-Behnken design was used in combination with single factor experiments to establish the optimal removal conditions as follows: citric acid concentration 0.06mol/L, ultrasonic power 220 W, ultrasonic treatment time 20 min, contributing to a removal rate of 98.5% and chromatic aberration of 3.149.Under this condition, the basic nutrient component, amino acids and fatty acids hadn't been affected. This removal procedure was simple and the obtained products had good quality with low cadmium level, so that it could be used in industrial production of Pyropia haitanensis.