Abstract: In this study, the SRAP markers were employed to analyze the genetic diversity and relationship between 56 spaghetti squash and 32 Cucurbita genus cultivated species (Including Cucurbita moschata, C. pepo and C.maxima). The results showed that: (1) There were 50 SRAP primer pairs selected from 285 primer pairs, which amplified a total of 713 bands via PCR. Amongst them, 586 bands were polymorphic with a percentage of 88.92%, which suggested that Cucurbita genus was rich in genetic diversity. (2) There were 586 bands generated within the 56 spaghetti squash accessions. 350 (59.7%) of these bands were polymorphic, which revealed that the genetic similarity of spaghetti squash cultivars was high. (3) the 56 spaghetti squash accessions could be clustered into five major sub-groups, according to the analysis on genetic similarity coefficient. Spagetti squash had the closest genetic relationship to C.Pepo; a closer relationship to Cucurbita moschata whearas its relationship with C. Maxima was farthest. According to the above results, we could confirm that the spaghetti squash could be regarded as a variationsubspecies of C. pepo.