It is important to evaluate postoperative blood flow and detect vascular thrombosis early to improve the transplanted free tissue and replanted finger salvage rate; however, a universal blood flow evaluation method has not been established. We used near-infrared spectroscopy （NIRS）as postoperative evaluation （n=62 patients). There were no cases of transplanted free tissue failure when we used regional saturation oxygen （rSO2） values 30% or more and total hemoglobin index （T - HbI） values less than 0.48. NIRS has no definite cutoff value. NIRS is an easy-to-use, non-invasive, and objective process that can be used regardless of experience. Using NIRS to evaluate postoperative blood flow is helpful when it is difficult to evaluate only the clinical process.