The author analyzed the main seasonal evolution modes of the Pacific sea surface temperature and their relations with the seasonal evolution of rainfall over eastern China and the atmospheric circulation over East Asia as well as the related physical processes by applying extended empirical orthogonal function (EEOF) analysis, correlation analysis, and composition analysis, etc, using the datasets of monthly sea surface temperature, atmospheric circulation, and monthly rainfall of 160 stations in China. The main results show that there are two dominant modes in the seasonal evolution of ENSO (El Niño/Southern Oscillation), including four types (El Niño persisting, La Niña persisting, La Niña switching to El Niño, and El Niño switching to La Niña). Obvious differences in the distribution and intensity of rainfall anomalies over eastern China are found between different modes and types of seasonal evolution of ENSO. For the types ENSO persisting and El Niño switching to La Niña, the distributions of rainfall anomalies are somewhat similar because both types occur under the background of El Niño in winter, spring, and early summer. But the distributions of rainfall anomalies are remarkably different in midsummer and autumn because they are under the influences of El Niño and La Niña, respectively. The rainbelt jumps northward slowly and is located further south for the former, whereas it jumps northward quickly and is located further north for the latter. The similar situation can be found for the types La Niña persisting and La Niña switching to El Niño, and the distributions of rainfall anomalies are somewhat similar in winter, spring, and early summer. But the rainbelt moves northward quickly and is located further north for the type La Nina persisting, while the opposite is true for the type La Niña switching to El Niño in midsummer and autumn. This is because rainfall is under the impacts of El Niño and La Niña respectively during that period. Therefore, not only the early signals of ENSO but also the possible evolution mode of ENSO should be considered in the prediction of rainfall over China under the influence of ENSO. The analysis of the physical processes that link different seasonal evolution modes and types of ENSO and rainfall over eastern China shows that different seasonal evolution modes and types of ENSO impact the distribution of rainfall over eastern China through influencing the western Pacific subtropical high and the zonal and meridional circulations in the westerly wind belt. The warm wet water vapor transport from low latitudes and cold air activities in the middle and high latitudes are also involved. The anti-cyclones (cyclones) over the Philippine islands and their adjacent regions, the equatorial Walker circulation, and the Northern Hemisphere Hadley circulation are important linkages between ENSO and the activity of the western Pacific subtropical high and the zonal, meridional circulations in the westerly wind belt.