By taking use of 481 mungbean germplasms that were collected from 21 countries (or regions), the phenotypic variations at nine qualitative traits and 12 quantitative traits were evaluated at four locations in a frame of three years. The abundant phenotypic variations were observed in these mungbean germplasms. The coefficient of variations of 12 quantitative traits ranged from 5.32% to 76.18% under different environmental conditions, of which, the grain yield per plot and the number of pods per plant had higher coefficient of variation; the genetic diversity index ranged from 1.573 to 2.078, and the plant height and 100-seed weight had the higher genetic diversity index. The growth period was observed to be significant or extremely significant positive correlated with other traits such as plant height, number of stem node and number of branches on main stem, thus implying an important role in mungbean morphogenesis. The cluster analysis suggested four major groups of which the first group included the germplasms showing dwarf, erect, large seeds and early-maturation. These germplasm resources might show a potential as excellent parent materials for breeding. For example, the 100-seed weight of a few accessions (e.g. C06287, Taolv 3, VC4059A and Sulv 1) were higher than 6.50g, which could be used as materials for improving the seed size of mungbean. The growth period of accessions C01075, C01234, and C01249 were shorter, which might carry functional genes causing early-maturation; Liaolv 28, VC1562A and Wei 9002-341 could be used as parent materials for lodging resistance breeding; C05199, C05202 and C05528 could be used as parent materials for mungbean bruchid-resistance breeding. Finally, the principal component analysis (PCA) of quantitative traits suggested that six principal component factors might contribute 83.41% of phenotypic variation. In summary, this article aims to provide a theoretical basis for genetic breeding and germplasm innovation of mung bean by comprehensively evaluating the genetic diversity of 481 mung bean germplasm resources.