Abstract: Maozhushan site, 30°39' 40”N, 118°57' 28”E, is located near Ningguo City, Anhui Prov- ince of eastern China. It lies on a hill and 25m above the river level of the Xijin River, a second tributary of the Lower Yangtze River.
During the first excavation in 1997, a pebble semicircle composed of more than 1100 pebbles including 154 stone artifacts was found. The human living floor is at the basal part of the reticular mottled red clay, which is 3 meters in thickness.
The assumed central camping is 10m long and 6m wide, it' s inner area being 19 m2, where no pebble was found.The semicircle is about 2m in width. More than 10 small rings 20 -30 cm in diameter among the body of semicircle.
The types of stone tools include scraper, chopper, pointed chopper, pick, and spheroid. The percentage of categories of stone artifacts is 19.5% flake, 24.7% core, 32.5% chunk, 6.5% chop- per, 5.2% scraper, 2.6% pointed chopper, 2.6% spheroid, 0.6% pick and 0.6% borer, etc.
The cultural layer is comparable with those of the Middle Pleistocene' s Chenshan site in Xuanzhou City.ESR dating of quartz grains assigned an age of about 0.6 mya.

Key words: Pebble semicircle; Maozhushan; Anhui Province; Middle Pleistocene