Abstract: Based on the four times daily NCEP-NCAR reanalysis dataset, the 850 hPa relative vorticity cyclone tracking method was employed to identify the genesis, lysis, and maturing regions, and the different track distributions, in Mongolian cyclones for the years 1948-2013 in spring. According to the different distributions of the Mongolian cyclone tracks, two types of Mongolian cyclones were defined:One with eastward-oriented tracks and the other with southeastward-oriented tracks. The interannual and interdecadal variations of these two categories with respect to the frequencies and intensities of Mongolian cyclones were also investigated. Meanwhile, the low-frequency background circulation patterns of the two categories were revealed. The main conclusions are as follows:(1) Mongolian cyclones mainly formed over the leeward side of mountains to the south and east of Lake Baikal and enhanced in northeastern China and eastern Mongolia. Most cyclones died out in Northeast Asia and its adjacent seas. (2) There was obvious decadal variation in the two categories of Mongolian cyclones. The frequency of the ‘east path’ Mongolian cyclones was below the norm in the 1950s, above the norm in the 1970s and 1980s, below the norm in the 1990s, and has shown an increasing trend since the beginning of the 21st century. The ‘southeast path’ Mongolian cyclones occurred less than average before the 1970s, more than average from the 1970s and mid-1980s, and then decreased again after 2005. (3) The positive phase of the Scandinavian pattern-formed by a negative anomaly center around the North Atlantic to the Mediterranean, a positive center around Scandinavia, a negative center around Lake Baikal, and the opposite over Japan-was the main background circulation of ‘east path’ Mongolian cyclones. The background circulation of ‘southeast path’ Mongolian cyclones was characterized by a negative height anomaly over West Russia, a positive height anomaly over the region from the Laptev Sea to Northwest China, and the Northeast China cold vortex circulation.