Objective To establish trans-vivo delayed type hypersensitivity (trans-vivo DTH) assay for evaluation of immune response status in renal transplant recipients. Methods Peripheral blood mononuclear cells (PBMC) were obtained from donors (n=13) and recipients (n=13) by Ficoll density gradient centrifugation. Sub-cell antigens were prepared by ultrasonication of PBMC from donors. PBMC from recipients, recall antigen EBV antigens and donor antigens were injected into the foot pads of CB-17 SCID mice accordingly. For negative control group, 7-9×10⁶ PBMC from recipients were injected. For donor antigen reactive group, 7-9×10⁶ PBMC from recipients and 10 μg donor antigens were injected. For positive control group, 7-9 ×10⁶ PBMC from recipients and 10 μg EBV antigens were injected. For linked immune suppression group, 7-9×10⁶ PBMC from recipients, 10 μg EBV antigens and 10 μg donor antigens were injected. The thickness of foot pads of mice was measured before injection and 24 h after injection, and the change of thickness of foot pads was calculated. The net change of thickness ≥ 63.5×10^-3 mm in positive control group was considered to be valid. Results Trans-vivo DTH assay in monitoring of 13 living related renal transplant recipients revealed that 8 patients (62%) were sensitized pattern, 3 patients (23%) were regulator pattern, and the other 2 patients (15%) were non-regulator pattern. Conclusion Response to donor antigens in living related renal transplant recipients can be monitored by trans-vivo DTH assay.