In this paper,the characteristics of precursory anomalies prior to the 2016 Menyuan M_S6.4 earthquake are investigated using the Load/Unload Response Ratio(LURR)method based on YRY-4 borehole strain data from the Golmud and Ledu stations,and the results are compared with those obtained using the conventional strain analysis method. the results show that no anomalies were identified in the original strain data,whereas significant anomalies were detected in the shear strain at the Golmud station prior to the earthquake. By contrast,neither obvious original-strain nor shear-strain anomalies were observed at the Ledu station. Clear precursory anomalies were captured by the LURR method at both stations,exhibiting a rise-peak-decline pattern consistent with the nonlinear damage evolution law preceding rock failure. In addition,a low b-value anomaly(b＜0.7)appeared in the region surrounding the Golmud station,whereas only a single LURR anomaly was detected at the Ledu station. These results indicate that the LURR method can effectively extract precursory information from borehole strain data and,when combined with b-value analysis,can provide a useful reference for strong earthquake assessment.