Objective To investigate the role of parenteral nutrition (PN) in patients undergoing hematopoietic stem cell transplantation (HSCT).Methods The clinical data of 106 patients who had undergone HSCT from January 2008 to September 2009 were retrospectively analyzed.These patients were divided into PN group (n =42) and non-PN group (n =64) based on their nutrition support modes and then compared in terms of time of hematopoietic reconstruction,oral mucositis,liver function,infections,and graft-versus-host disease (GVHD).The PN group was further divided into riboflavin group,glutamine group and structolipid group to explore the roles of different nutrients.Results In the 42 patients receiving PN support,33 patients were treated with riboflavin,24 with glutamine,and 26 with structolipid.In the PN group and non-PN group,the incidence of oral mucositis was 31.0％ and 51.6％ (P =0.036),the incidence of infections was 42.9％ and 46.9％ (P =0.898),the incidence of GVHD was 21.4％ and 31.3％ (P =0.267),the ALT level was (49.5 ±9.8) U/L and (69.9 ± 10.9) U/L (P =0.196),the average time of granulocyte reconstruction was (11.6 ± 0.3) days and (12.3 ± 0.3) days (P =0.187),and the average time of platelet reconstruction was (14.1 ±0.9) days and (13.3 ±0.4) days (P =0.386),respectively.The incidence of oral mucositis in the riboflavin group (27.3％) was lower than those in the non-riboflavin group (44.4％) and non-PN group (51.6％) (P =0.073).Among glutamine group,non-glutamine group,and non-PN group,no statistically significant differences were found in the incidence of oral mucositis,infection,GVHD,ALT level and hematopoietic reconstruction time (all P ＞ 0.05).The ALT level in the structolipid group [(38.7 ± 4.9) U/L] was lower than those in medium-and long-chain fat emulsion group [(68.5 ± 23.0) U/L] and non-PN group [(69.9 ± 10.9) U/L] (P =0.243),but the differences were not statistically significant.Conclusions Patients who have undergone HSCT can benefit from proper PN.Riboflavin may prevent oral mucositis and structolipid may be equally safe for liver as medium-and long-chain fat emulsion.The role of glutamine in this condition needs further research.