Abstract： Objective To investigate the effectiveness and safety of a short term of CsA interval in TAC related new onset diabetes mellitus (NODAT) after renal transplantation.Methods Clinical data of 19 NODAT patients in TAC-based regiment were analyzed. Two groups of patients with NODAT were identified.In 7 patients,TAC was converted to CsA,and 6 months later to TAC again (converted group); in 12 patients,TAC was given continuously (control group).Results In the converted group,FPG was decreased from 8.3 ± 3.9 mmol/L at the time of conversion to 5.6 ± 1.8mmol/L 12 months later (P＜0.01),and in the control group,that was 8.1 ± 3.5 mmol/L and 8.0 ±3.0 mmol/L respectively (P＞0.05).There was a great significant difference between groups (P＜0.05).In the converted group,HbA1c levels were decreased from 6.8％ ± 0.8％ to 6.1％ ± 0.4％ at 12th month (P＜0.05),while in the control group,HbA1c levels were 6.9％ ± 0.7％ to 6.8％ ±1.5％ (P＞0.05).There was also a great significant difference between groups (P＜0.05).After follow-up for 12 months,4 (57.1％) of converted patients no longer had diabetes versus 0％ in the control group (P＜0.01).Blood pressure and lipid levels were stable after conversion.The conversion was safe in terms of graft function and acute rejection episodes.The 1- year patient survival and graft survival rate was 100％. Conclusion This primary study suggests a significant improvement of glucose metabolism after a short term conversion to CsA in renal transplant patients with NODAT