Objective To explore the effect of body mass and body mass index (BMI) on proton hepatic MRS water suppression at 3.0T. Methods The prospective study of hepatic proton MRS was performed with GE Signa Excite HD 3.0T system and eight-channel torso phased-array coils using PRESS sequence in 44 healthy subjects. Liver spectra were collected with TR of 1500 ms, TE of 30 ms, VOI of 2 cm×2 cm×2 cm and NSA of 64 times. Areas and heights for metabolites resonances were caulculated. Results Group with small mass has lower height ([161.2±8.5] cm vs [167.7±6.2])cm, lower BMI ([20.8±2.3] kg/m~2 vs [25.6±2.6]kg/m~2), better water suppression effect (min-max: 90-96 vs 65-94;median: 94 vs 93), smaller height (min-max: 1.41×10~4-5.76 ×10~5 vs 3.45×10~4-1.75×10~6;median: 9.00×10~4 vs 2.58×10~5) and integrated area (min-max: 4.27×10~4-2.00×10~7 vs 1.24×10~5-5.00×10~7;median: 2.64×10~5 vs 1.19×10~6)of Lip2 than larger weight group. Standardized lipid content (min-max: 0-0.11 vs 0-0.96;median: 0.01 vs 0.04) was less. Group with lower BMI had lower weight ([55.2±8.2]kg vs [71.2±7.8]kg), smaller age ([33.2±11.9]years vs [45.6±9.4]years), better water suppression effect(min-max: 90-96 vs 65-95;median: 94 vs 93) smaller of height (min-max: 1.41×10~4-5.76×10~5 vs 3.45×10~4-1.75×10~6;median: 7.37×10~4 vs 2.11×10~5) and integrated area (min-max: [4.27×10~4-2.00×10~7] vs [1.24×10~5 -5.00×10~7];median: 2.64×10~5 vs 1.19×10~6) of Lip2 than larger weight group. Standardized lipid content (min-max: 0-0.08 vs 0.01-0.96;median: 0.01 vs 0.04) was less. There was significant correlation among water suppression, weight (r=-0.478, P=0.001) and BMI (r=-0.494, P=0.001). Conclusion Lipid accumulation in the liver may be the result of increased fat portion of the body depending on mass and BMI, and hinder to achieve effective water suppression.