We counted the heronries at two study areas in China, where important but unknown numbers breed. At Poyang Lake, within a 1,800 km2 area, we found ten heronries with Little Egret (Egretta garzetta), Intermediate Egret (Egretta intermedia), Great White Egret (Ardea alba), Cattle Egret (Bubulcus ibis), Chinese Pond Heron (Ardeola bacchus), and Black-crowned Night Heron (Nycticorax nycticorax), and at Tai Lake we found five heronries within a 4000 km² area. Heronry size ranged from a few hundred nests to 36,400 nests. Several heronries were located within human settlements, in contrast with the sites used in Europe and in North America, where herons tend to avoid human disturbance. An extrapolation of the mean densities observed at the two study areas, for all the zones of mainland China that are cultivated mostly with rice, provide a first estimate of a total numbers of up to some five million nests of herons and egrets, which is much higher than previously suggested for China.