Abstract:Based on the meteorological observation data, NCEP/NCAR atmospheric reanalysis data and NOAA SST data, this paper analyzes the main climate characteristics and discusses the cause diagnosis in China in the spring of 2022 by using correlation and synthesis analysis methods. The results show that in spring 2022 (March-April-May, MAM), the process of monsoon rain belt in China is earlier generally. China experienced the warmest spring since 1961, with an average temperature reaching 12.1℃. The MAM precipitation averaged (154 mm) in China was close to normal, but the precipitation reached unprece-dentedly high values in Southwest China, showing distinguished spatial diversity. A northwest-southeast anomalous circulation pattern “―＋―” was formed in the middle-upper troposphere, which started from the north of Ural Mountains, via the Tibetan Plateau, and to the Indo-China Peninsula. Such pattern allowed the low-latitude anomalous easterly airflow to converge with southward northeast-northerly airflow in Southwest China, which further facilitated water vapor transport and intersection of cold and warm air, finally causing abnormally more precipitation in Southwest China in spring 2022. In addition, the La Ni〖AKn~D〗a event (autumn 2021 begins) acted as an important forcing factor for excessive spring precipitation in Southwest China. The sustained development of the La Ni〖AKn~D〗a in spring 2022 led to more typically anomalous circulation patterns than normal development, exacerbating the excessive precipitation in Southwest China.