Abstract: To obtain relevant leaf color data of current purple leaf lettuce and establish grading standards, the study used colorimeter and HPLC to measure anthocyanin contents and color indices of 40 different colored lactuca cultivars. Correlation analysis between the color parameters and contents of anthocyanin was conducted so that to establish a grading system. According to special color parameters and anthocyanin content, purple leaf lettuce could be divided into five levels, i.e. green, light purple, middle purple, purple and deep purple, and a leaf grading system was established. According to purple part distribution on leaf, purple leaf lettuce could be divided into four categories, i.e. skirt purple, gradient purple, all purple leaves and spotted purple. This paper provided a scientific method to measure and evaluate leaf color traits, thus to help cultivate new varieties of purple lactuca.