Polyploid breeding is an important way to innovate cassava germplasms. In order to explore the effects of cassava polyploidization on plant phenotype， plant growth potential， and photosynthesis-related physiological indicators， we analyzed 28 quality traits and 18 quantitative traits of 8 cassava varieties and their corresponding induced autotetraploid resources. The results showed that 8 cassava varieties showed differences in 40 phenotypic traits. The leaf center leaflet shape traits were significantly different between the diploid varieties and their autotetraploid resources. The majority of autotetraploid resources shows reduced ratio of lobe length to lobe width of central leaf lobe， shortened plant height， and reduced number of root tubers compared with corresponding diploids . Only the roots weight per plant of Xinxuan 048 and South China No.12 autotetraploids increased significantly， and the dry matter content of Nanzhi 199 and South China No.14 autotetraploids increased significantly. A survey of plant growth potential indicators found that most of the autotetraploid varieties have significantly lower plant height than diploids. And most of the autotetraploids have lower leaf numbers than the corresponding diploids during the same period， and reach the highest leaf holdings from late August to early October. The effect of chromosome doubling on the stem diameter of each variety is not obvious. The net photosynthetic rate of 8 varieties all shows significantly higher rate in autotetraploidsthan diploids. This study clarified the phenotypic differences， growth and development characteristics between diploids and autotetraploids of 8 varieties， analyzed the impact and occurrence rules of chromosome doubling on plants， and provided materials and theoretical basis for cassava polyploidy research.