AIM: To observe the effect of Lycium barbarum polysaccharide (LBP) on rat retinal ganglion cells (RGCs) in vitro. METHODS: Retinal cells of neonatal Sprague-Dawley rats were collected 1 to 3 days after birth, and co-cultured with different concentrations of LBP for 24 hours. Absorbance values (OD) were recorded using MTT assay for calculating survival rates. RESULTS: All the test groups had protective effects on RGCs. The group with 10mg/mL concentration of LBP had the most significantly difference of OD value compared with that in control group (P<0.01). CONCLUSION: LBP can increase the survival rate and promote the growth of mixed cultured rat RGCs.