Occurrence and distribution of eight selected antibiotics were screened at four sewage treatment plants (STPs). Individual concentrations in raw influent and final effluent from the four STPs ranged from 16 to 1987 ng x L(-1) and from 16 to 2054 ng x L(-1), respectively. The other analytes were only detected in a few samples with lower concentrations. Antibiotics can not be removed completely at the four STPs with the highest removal efficiency reaching to 81%. Remarkable differences of the daily environmental loads (the sum of the amount in the final effluent and sludge) of the five most frequently detected compounds at the four STPs were found with mass data ranging from 0.5 to 828 g. The daily consumption per person in the charged area of selected STPs showed that more compounds, especially the erythromycin-H2O, were consumed each day in Guangzhou than in Hong Kong.