Objective: To investigate bone mineral density of college students with masked obesity, and to provide theoretical basis for bone density improvement and osteoporosis prevention in college students. Methods: Participants were enrolled from universities and colleges. A total of 518 low-weight or normal-weight students were included and were classified according to the criteria of masked obesity, dual-energy X-ray test was used to detect the percentage of body fat and bone mineral density of college students in each group. The differences in bone mineral density between masked obesity and non-masked obesity groups of different genders were compared, and the correlation between body mass index, body fat percentage and bone mineral density was analyzed. Results: Among the low-weight male college students, the whole body bone mineral density, t-value and Z-value of masked obesity group were lower than those of the nonmasked obesity group [(1.82±0.04,2.01±0.22)g/cm 2; (-1.10±0.24,-0.02±0.15); (-0.94±0.64,-0.01±0.43)(P<0.01)]. Among low-weight male college students, bone mineral density of the upper limbs, thighs, ribs, and pelvis of the masked obesity group was lower than that of the non-masked obesity group. Among low-weight female college students, body bone mineral density of masked obesity group was lower than that of the non-masked obesity group [(1.13±0.48,1.31±0.29)g/cm 2; (P<0.05)]. Among low-weight female college students, bone mineral density of head, upper limbs, thighs, and trunk of masked obesity group was lower than that of the nonmasked obesity group. In male college students, body mass index was positively correlated with bone mineral density, T-value and Z-value (r=0.69, 0.68, 0.61, P＜0.01) while body fat percentage was negatively correlated with bone mineral density, T-value and Z-value (r=-0.52, -0.51, -0.49, P＜0.01). In female college students, body mass index was positively correlated with T-value and Z-value (r=0.46, 0.26, P＜0.01), and body fat percentage was negatively correlated with T-value and Z-value (r=-0.22, -0.23, P＜0.01). Conclusion Compared with normal-weight college students, depletion of bone mineral density among masked obesity students is observed. It is of great significance to pay attention to bone mineral density of college students with masked obesity and implement intervention to prevent osteoporosis timely.