This paper,based on the index of Jiangsu Meiyu,analyzes the characteristics of Meiyu precipitation in Nanjing in 2018,and the associated circulation causing the anomaly Meiyu,by using the daily precipitation data of Nanjing and daily NCEP/NCAR reanalysis data.The results show the following:1) The Meiyu in Nanjing in 2018 was characterized by the later beginning date,nonuniform distribution of Meiyu precipitation in space,and a significantly lesser amount of Meiyu precipitation (80% less than the climatic mean in the southern Nanjing).2) The previous trough in westerlies was active,and this caused the Northwest Pacific Subtropical High (NPSH) to occur more southerly than normal.In such a case,the seasonal northward of NPSH occurred late,which in turn resulted in a late beginning date of Meiyu.Meanwhile,the South Asia High (SAH) in 2018,which was stronger and more northeastward than the climatic mean,was conducive to a late beginning of Meiyu.3) During the Meiyu period,the ridge of NPSH jumped to north sharply and the SAH was stronger and more northeastward than the climatic mean.These circulations,together with the weak activities of the Northeast China cold vortex,led to a northward conglomeration between cold air and warm air,as well as significantly less rainfall during the Meiyu period in the region along the Yangtze River.4) The amount of Meiyu precipitation in Nanjing shows a negative correlation with the north-south span of the NPSH from June to July.5) In the years of strong East Asia summer monsoon,the Meiyu precipitation in the central and northern parts of Nanjing was less than the climatic mean.These insights will be useful in the forecast of Nanjing Meiyu.