We investigated the spatial-temporal ozone variations in eastern China by using surface ozone observation data from 222 cities of 20 provinces in eastern China and global reanalysis data for wind throughout 2015 and 2019, and evaluated the influence of the ozone photochemical transport from upwind directions to downwind directions in the background of Asian Summer Monsoon (ASM). It is shown that ozone levels over eastern China are high in winter, while low in summer, and increase in the order of southeast, east, northeast and north China. Ozone levels are significantly higher in north and northeast China located in mid-high latitudes than in east and south China located in mid-low latitudes. Diurnal variations of ozone levels exhibit similar single-period patterns that remain low at night, gradually rise in the early morning and peak during afternoon and twilight in various seasons over various cities, showing typical photochemical controlling characteristics. In spring, ASM starts to influence eastern China and cause a large region of enhanced ozone over east, north and northeast China. In summer, ASM persistently transports ozone and its precursors from south and east China to north and northeast China which react photochemically by solar UV radiation thus leads to summer ozone pollution in north and east China.