Abstract: Regarding the low utilization rate of injected water at the middle and late stages of water flooding in the fractured-vuggy reservoirs of Tahe oilfield, technological policy should be optimized and adjusted. The available evaluation indexes cann’t be used to effectively evaluate the injected water utilization due to the overflowing of injected water resulted from strong heterogeneity and developed fractures of the reservoirs. Based on the analysis of the characteristics of the injected water utilization in the fractured-vuggy reservoirs and according to the directions where the injected water goes underground, 4 evaluation indexes are presented such as pressure rising index, oil displacement index, channeling index and leakage index and a calculation method is proposed. The actual application in the Well group TK713 of Unit S80 in the District 6 of Tahe oilfield shows that the evaluation method can quantitatively characterize where the injected water goes underground and the evaluation result could guide adjustment program making.