Winter cold air activity was examined in terms of the concurrent intensity variation between the East Asian polar front jet (EAPJ) and subtropical jet (EASJ) using NCEP/NCAR reanalysis dataset and observed daily temperature datasets from stations in China. The regional averages of 300-hPa wind over two domains (45°-60°N, 70°-110°E; 27.5°-37.5°N, 130°-160°E) were used to measure the strength of the East Asian polar front and subtropical jets. The results were classified into four situations based on jet intensity changes: strong EAPJ corresponding to strong EASJ(SS); weak EAPJ corresponding to weak EASJ (WW); strong EAPJ corresponding to weak EASJ(SW); and weak EAPJ corresponding to strong EASJ (WS). Then, the features of the winter cold air activity were analyzed with respect to cold air intensity, route, duration, and origin, taking the jet intensity changes into account. During the SS situation, it was found that relatively weak cold air activity with short duration intrudes into the inland and coastal regions of northeastern China from Inner Mongolia. The genesis of the cold air can be traced back to the region to the east of Novaya Zemlya. During the WW situation, strong cold air activity with long duration intrudes into most parts of China from northern Xinjiang. The genesis of this cold air can be traced back to the west of Lake Balkhash. During the SW situation, relatively strong cold air activity with short duration intrudes into North China from the northeast, with no obvious temperature drop . The genesis of the cold air in this situation can be traced back to western Siberia. During the WS situation, relatively weak cold air activity intrudes from Inner Mongolia, affecting almost all of eastern China. The genesis of this cold air can be traced back to the west of Lake Baikal. Circulation features corresponding to the different jet intensity changes were also analyzed. During the WW situation, the Siberian high and Aleutian low are relatively strong and weak, respectively; moreover, the East Asian trough is relatively deep, and the northerly wind in eastern China is strong. During the WS situation, both the Siberian high and Aleutian low are relatively strong, the East Asian trough is deep, and the northerly wind in eastern China is weak. For the other two situations (WS and SW), the Siberian high is relatively weak, the East Asian trough is shallow, and the northerly wind in eastern China is weak.