In this paper,the temporal and spatial evolution characteristics of W_q values before earthquakes above M_S5.0 in Qinghai,Xinjiang and Tibet since 2010 to 2020 were systematically summarized. The Xinjiang Yutian M_S6.4 earthquake on June 26,2020 and the Tibet Nima M_S6.6 earthquake on July 23,2020 are taken as examples. The research results suggest that:① Strong earthquakes generally occurred during the W_q values expansion or expansion-decrement periods and about 81% occurred within 9 months after the appearance of the W_q anomaly. ② The epicenters of the earthquakes were generally near the W_q values anomaly expansion areas or the areas of expansion-decrement recovery and nearly 70% of the earthquakes occurred in the area of W_q value anomaly. ③ With a correlation coefficient(R)of 0.85,the statistical relationship between the magnitude and the areas of abnormal W_q was established,which provided a quantitative model for the prediction of medium-short term earthquakes in Qinghai,Xinjiang and Tibet Areas. The prediction effect of W_q value method for M_S6.0 ～6.9 earthquakes in Qinghai,Xinjiang and Tibet area(with hit rate of 61%)was better than that of M_S5.0 ～5.9 earthquakes(with hit rate of 26%). Therefore,the model is significant for the prediction of medium-short term(within one year)strong earthquakes in the area with lower ability of geophysical observation in China.