〔Abstract〕 Objective To investigate the growth trajectory of low birth weight infants(LBWI) in infancy, and to establish a growth model of physical development index percentile for LBWI. Methods A total of 261 cases of LBWI were selected in the urban area of Hefei to establish a research cohort. The LMS method was used to establish the percentile curves of age-specific body weight, age-specific length for LBWI infants in Hefei City. Results LMS method was used to fit the body mass and body length curves, and the physical development index percentile curve of LBWI was established. The reference values of body mass and body length percentile of LBWI at different months of infancy were obtained. The fitting effect of growth curve was good. Conclusion This study from the body quality, long established different genders LBWI infantile growth standard reference value and growth curve, to assess LBWI infant growth situation and predict infant disease such as clinical practice to provide the reference and help to understand the Hefei LBWI physique growth characteristics and trajectory, for monitoring LBWI growth and provide reference for evaluation of nutritional status.