The phenotypic traits of 153 lettuce germplasm resources from United States and China were identified, which included the leaf traits, plant trait, bolting, etc. The results showed that coefficient of variation(CV) values of the 15 phenotypic traits ranged from 7.05% ( The flowering period) to 49.85% ( Leaf margin ) with an average of 28.98%. The diversity indexes(H’) of the 15 phenotypic traits ranged from 0.3 (degree of undulation of leaf blade margin) to 1.56(The leaf shape). Based on SAS clustering analysis of 15 phenotypic traits, the 153 collections at Euclidean distance of 15, could divided into 4 categories. The results show that the I and IV group contains 60 and 65 materials, the others group contain less material. In general, variation of phenotypic traits and diversity index is higher in those lettuce, which has rich variation and diversity.