Abstract: A definition of stationary wave anomalies is given based on the Lorenz decomposition of the atmospheric circulation, and monthly variations of the zonal component of stationary waves relative to the mean are illustrated. A deviation index ( )for global (local) stationary waves is used to analyze the stationary wave anomalies in the latitude band 30°-60°N, where the stationary waves in the Northern Hemisphere 500hPa geopotential height field is significantly strong. The following results are obtained: (1) the devoation index characterizes the spatialtemporal variance of global stationary waves in the 30°-60°N belt, and this anomalous belt advances southward and then retreats northward in the course of seasonal march. Steady stationary waves occur in mid-latitudes (35°-55°N) in winter and in the subtropical zone (south of 35°N) in summer. Specifically, they are associated respectively with the major troughs of East Asia and North America and the weaker European trough in winter, and the relatively steady subtropical high system in summer. A high value center of the deviation index appears at 35°N in spring and 50°N in summer, which reflects the seasonal variation of the strength of stationary waves and that of their zonal distributions. (2) The degree of deviation for local stationary waves clearly shows a zonal asymmetry. The steady zones of stationary waves are always located in the areas controlled by strong troughs or ridges, whereas the anomalous ones are in the areas where the stationary wave intensity is weak. The degree of deviation for local stationary waves in the subtropics (south of 35°N) is larger in winter than in summer, and the reverse is true in the mid-latitude region (north of 35°N). The summertime distribution of the deviation index on the whole shows a rather complicated structure. However, North Europe is the most anomalous area for local stationary waves, as represented by a high value of in both summer and winter, while over the North American Continent (about 120°-60°W), is slightly less than 1 in summer, indicating that the stationary waves in this region are more steady than those over other mid-and high-latitude regions. (3) From North China to the Northwest Pacific, there is a high value zone of in summer, with its center (45°N，130°E) located to the east of Heilongjiang Province, which impacts the northern areas of China. This may explain why these areas experience large interannual climate variabilities in summer. It is proposed that the degree of deviation is an intrinsic characteristic of stationary waves, and it can be of the same importance as the intensity and the energyspectrum structure of stationary waves in the study of the general circulation system.