Abstract: To study the correlation between yield of storage roots and above-ground agronomic traits, grey relational analysis was performed using sweet potato harvested from the Research Station at Tai’an city. Thirteen agronomic traits of sweet potato have been studied. Our results demonstrate that the five agronomic traits showing strong correlation with fresh weight of storage roots in order of importance are the fresh weight of branch petioles, the number of branch leaves, the total fresh weight of above-ground biomass, the fresh weight of branches and the number of branches. The top five traits significantly contributed to dry weight of storage roots are the fresh weight of branch leaves, the length of branches, the fresh weight of branch petioles, the number of branches and the number of branch leaves. Among the meteorological factors analyzed, the temperature was proved to be more important than humidity for a higher yield. Our study suggests that different traits need to be considered besides the major yield factors in order to reach a balanced objective in sweet potato breeding program.