Abstract: Aiming at the meteorological forecast and corresponding service for steep descent of temperature in the northeastern Qinghai-Tibet Plateau, based on the daily minimum temperature data of 68 meteorological stations from 1961 to 2017, we discussed the threshold values in the process of steep descent of temperature and its climate characteristics by employing the means of trend analysis and correlation analysis, and built a forecast diagnostic model with NECP/NCAR (2.5°×2.5°) SST field and height field. The results showed that: (1) it was more in line with the actual situation to use the improved steep descent of temperature indexes to summarize the characteristics of the occurrence of cold wave; (2) due to the influence of landform and mountain barriers, there were obvious differences in the regional distribution of the times of steep descent of temperature in the northeastern Qinghai-Tibet Plateau, and the times of steep descent of temperature in the mountainous areas and eastern areas at higher altitudes were significantly more than those in the basins, the times of 24- hour cold wave in the southern mountain areas were more than those of 48-hour and 72-hour; (3) in recent 57 years, the frequency of regional cold waves showed a general downward trend, and the deceleration rate in the south and the north was -0.5 times/10 a and -0.4 times/10 a, respectively; which passed the significance test, the deceleration rate in the northwestern basin area was -0.1 times/10 a, which failed to pass the significance test; (4) the moving path of high cold air was a key signal for the prediction of steep descent of temperature. The research results could provide a basis for the decision-making concerning agricultural and animal husbandry resources and tourism resources.