To investigate the protective effects of Polygonatum cyrtonema Hua polysaccharides(PCP) and PCP-1 on immune injury induced by chloramphenicol.Methods:The crude polysaccharides were obtained by water extraction and alcohol precipitation method，and PCP was obtained after protein removal and pigment removal.DEAE-sepharose Fast Flow chromatography column and HW-55F gel column were used to elute PCP.The eluent was collected，condensed under pressure，and freeze-dried to obtain purified PCP-1.Transgenic zebrafish with 2 days of post-fertilization(2 dpf) as experimental animals were treated with different concentrations of chloramphenicol.By comparing the number of neutrophils in the tail of zebrafish，the optimal modeling dose of chloramphenicol was determined，and the immunosuppression model of zebrafish was established.PCP and PCP-1 with different concentrations were added and incubated for 24 h，respectively，and the number of neutrophils from the cloaca to the tail of zebrafish was taken to investigate the immune-enhancing effects of PCP and PCP-1.Results:PCP-1 was a homogenous polysaccharide with a molecular weight of 3 350 Da.As compared with the control group，the number of neutrophils in the chloramphenicol group was significantly reduced(P<0.01).Compared with the chloramphenicol group，both PCP and PCP-1 increased the number of neutrophils in zebrafish within the experimental dose range(P<0.01)，and the dose-response relationship was obvious.Conclusion:Both PCP and PCP-1 can enhance immune activity and ameliorate immune injury to some extent.