Abstract: During the cryogenic freezing rain and snow weather at the beginning of 2008(including four weather processes), the main reason for this peculiar weather was that the cold air and the warm air confronted each other for a long time. The quasi-stationary front in South China was stable and less movable. The frontal slope was gentle, and ▽Θse intensified gradually along longitude and vertical direction. The inversion ( <0 ) was strong. There were several-layers frontal zones in the upper lever of the foreside of the main frontal zone. When the front was the strongest, the temperature difference from the south to north within the 10 latitudes extended to more than 20 ℃. The moving tendency, extension and the extending height of the moisture areas which the relative humidity was larger than 90% corresponded well with the four processes. The distribution of the frontogenesis was consistent with the large areas of the ▽Θse, and it tilted northwards with the height. Frontogenesis was taken place more times in area of the quasi-stationary front in Guizhou bounded Yunnan. The less movable frontogenesis center in South China was one of the reasons for the long-maintaining of the quasi-stationary front in South China during the cryogenic freezing rain and snow weather. The movement of the north-south wind boundary was consistent with the southward advance tendency of the four processes. All these four processes were companied by the southerly low level jet. When the subtropical high level jet and intensified gradually and extended downwards, the low level jet intensified. The high PV tough extended downwards during every process, while that in high-latitude was coincident with the main frontal zone in the middle-high level, while the high PV tough in middle-latitude corresponded well with the subtropical frontal zone. MPV2 as the horizontal component of the moisture potential vorticity was small, but corresponded well with the four processes. The flow on the isentropic surface of the upper and lower frontal zone boundaries could better reflect the characteristics of the upper and low boundaries of the quasi-stationary front in South China. There was easterly wind on the 290 K isentropic surface (below the low boundary of the front)in Guizhou, which was the main reason for the long-maintaining of the low level cold air-mass in Guizhou and most areas to the south of the Yangtse.