[Objective] The research' aimed to reveal the relationship between the ploidy of melon and drought resistance and provide theoretical basis for the drought-resistant breeding of polyploid melon.[Method]The growth indices,water situation,chlorophyll content,soluble sugar content,proline content in the leaves of diploid and tetraploid pellicle melon in seedling stage under water stress were determined and compared.[Result]Under water stress,the plant height,stem diameter,dry matter weight and chlorophll conte...