In this experiment, phenotypic traits, such as the height of plants, thickness of stem, number of stolons,number of minituber and diameter of tuber were determined using Chunshu No.3, Chunshu No.5, Favorit and Atlantic as materials. Photosynthetic rate, stomatal conductance, transpiration rate and inter cellular CO₂ concentration were also tested and correlation of yield traits analyzed. The results showed that the yield of‘Atlantic’was the largest, the number of minituber was 68.33, and the growth rate of tubers was 4.5 times faster than that of Favorit. The yield of tubers was negatively correlated with intercellular CO₂ concentration, and positively correlated with the number of stolons, photosynthetic rate, stomatal conductance and transpiration rate.