Abstract:In order to investigate the genetic diversity of cucumber breeding cultivars, 19 fruit appearance traits of 138 bred varieties cultivated in green-house which belong to different ecotypes were surveyed. The results showed that the genetic diversity index of qualitative traits of tested varieties was less than that of the quantitative traits. And the genetic diversity index of fruit appearance of different ecotype varieties was arranged as North-China Ecotype>South-China Ecotype>European Greenhouse Ecotype, the genetic diversity index of qualitative traits arranged as South-China Ecotype > North-China Ecotype >European Greenhouse Ecotype, and that of quantitative traits arrayed as North-China Ecotype>South-China Ecotype>European Ecotype. By Principal coordinate analysis(PCO) all these bred cultivars were divided into three parts: Part I are mainly North-China Ecotype, Part II mixed distribution of South-China Ecotype and European Ecotype, Part III European Ecotype. And the PCO result showed that there was gene interflow between Part I and Part II. The sparse papilloma and light skin type were separated in the offspring through selfing the gene-exchanged cultivars of North China type, which .validated the results of gene communication between Pat I and Part II germplasm. Representative cultivars of three ecotypes were selected by evaluation of their fruit appearance traits according to the demand of cucumber production. And also we gave some advice for the next cucumber breeding work on the reference of fruit traits of bred varieties.