A 50-year-old female patient received the first infusion of Rituximab for the treatment of phospha-tase A2 receptor-associated membranous nephropathy,but 24 h urine protein increased significantly at 1 day after medi-cation,and the 24 h urine protein quantification returned to pre-drug levels after 18 days.When rituximab was injected again later,the same symptoms as above appeared,which was considered to be the adverse reaction of rituximab,and the increased urine protein may be associated with the loss of the drug from urine.In this paper,adverse reaction of 1 case of urine protein increase caused by rituximab was analyzed and reported,so as to attract clinical attention.