By using conventional surface observation data, sounding data, automatic weather station data with an interval of 1 h, NCEP/NCAR reanalysis data (1°×1°, 6 h), and ERA5 reanalysis data (0.25°×0.25°, 1 h), the types and spatial-temporal distribution of forms of precipitation, transformation of phases, and physical mechanism of phase inversion are discussed and summarized based on 12 cases of snowfall processes induced by Changjiang-Huaihe cyclone from 1999 to 2013 in Shandong Province. The results are shown as follows. 1) There are various forms of precipitation in snowfall processes induced by Changjiang-Huaihe cyclone, such as rain, snow, sleet, hail, ice particle, graupel, snow grain, and glaze. Ice particle also acts as a transition form of precipitation in transformation of phases besides sleet. 2) Hail, ice particle, graupel, snow grain, and glaze appear most frequently in February, followed by March. Thundersnow occurs often in February and March. 3) Rain often occurs in the southeast of Shandong Province and the south of Shandong Peninsula, while snow often appears in the northwest of Shandong Province. In addition, thunderstorm occurs in the middle and western part of central Shandong Province and the south of Shandong Province, especially the southeast of Shandong Province. 4) The transformation from rain to snow is the basic phase change in snowfall process by Changjiang-Huaihe cyclone. Based on existence of rain and snow boundary, the transformation of phases can be categorized into two kinds, one is typical transition from rain to snow, the other one is without obvious transition from rain to snow. There are significant differences in synoptic systems. 5) Large-scale phase inversion phenomenon tends to occur near the boundary between snowfall area and rainfall area. The zone of phase inversion, with the same orientation of surface inverted trough, is located behind surface inverted trough. Phase inversion can be caused by temperature increase resulted from warm temperature advection at lower troposphere and shallow warming resulted from diurnal variation of temperature near surface around noon before cyclogenesis. The two factors both are closely related with the development of surface inverted trough.