Abstract: Based on the daily temperature data of 437 meteorological stations in Beijing, Tianjin, Hebei, Shandong and Henan provinces(municipalities directly under the central government) and global daily average reanalysis data produced by the National Centers for Environmental Prediction(NCEP) and the National Center for Atmospheric Research(NCAR) of the United States, the characteristics of extreme heat events and its causes in China during June to July of 2023 in North China and Huanghuai region were analyzed using climate statistical diagnostic methods. The results showed that the average temperature and the mean maximum temperature in June and July 2023 in North China and Huang-huai were both the highest in the same period since complete meteorological observation records were available since 1961. The average temperature and the mean maximum temperature in the five provinces of Beijing, Tianjin, Hebei, Shandong and Henan were significantly higher than normal, the average temperature and mean maximum temperature in Beijing, Hebei and Tianjin were the highest in the same period since 1961. The number of hot days in Beijing, Hebei and Tianjin was also the highest in the same period since 1961. There were 200 national meteorological stations in North China, Huanghuai where the daily maximum temperature reached or exceeded 40℃.The daily maximum temperature of 126 stations reached the monitoring standard of extreme events, among which 26 meteorological stations such as Jingxing in Hebei, Linzhou in Henan, and Tanghekou in Beijing have reached or exceeded historical extremes. The comprehensive intensity of high temperature processes in North China, and Huang-huai region from June 21 to July 9 in 2023 ranks first among all regional high temperature processes in China in the past 33 years. The analysis shows that global warming is the general background to the occurrence of extreme high temperature and that atmospheric circulation anomalies are the direct causes of the occurrence and extremes of high temperatures.