Based on China"s high-resolution grid rainfall data, NCEP/NCAR and ERA-Interim reanalysis data from 1979 to 2018, the relationship between the interannual variation of the main mode (southern concentrated pattern) of the quasi-biweekly oscillation (QBWO) of diabatic heating over Tibetan Plateau (TP) during boreal summer and rainfall anomaly over eastern China is investigated. In the year when the interannual intensity of QBWO over TP is strong, there is a significant positive correlation between summer rainfall anomaly in the south of the Yangtze River and QBWO over southern TP; in the weak years, the rainfall anomalies in the Jianghuai region and South China characterize a dipole pattern. In addition, in the strong (weak) years, the low-latitude intraseasonal signal originating in the Northwest Pacific region mainly shows a westward (northwestward) propagation, and the mid-high-latitude quasi-barotropic intraseasonal signal mainly shows a southward (southwestward) propagation. The combined effect of the signals from low latitudes propagating westward (northwestward) and the signals from mid-to-high latitudes propagating southward (southwestward) cause different abnormal rainfall patterns in China. The low-latitude QBWO signal propagating westward (northwestward) weakens and disappears after reaching the Arabian Sea (southeast of TP). The southward (southwestward) signal in the mid-high-latitude converges with the westward (northwestward) signal in the low-latitude, and then continues to propagate westward, and finally weakens and disappears.