Sewage irrigation has been paid more attention due to its adverse effects on soil and crops.An experiment was carried out in a greenhouse equipped with a drip irrigation system to investigate the distribution patterns of heavy metals (Hg and As) and tomato development,yield and fruit quality under sewage irrigation.Results showed that significant spatial variation of heavy metal contents was observed in soil profiles.Hg and As were enriched in the 10~30 cm layer,showing close correlation between them,which indicated that the soil environment was seriously affected by external pollutants.Generally,sewage irrigation influenced growth of tomato fruits and its quality,as shown by a lower growth rate,7 68% lower yield,46.2% higher soluble solid content,76.76% higher Vccontent,55.84% lower protein content and similar contents of the acidity and total soluble sugar than with freshwater irrigation.Sewage irrigation also increased Hg content by 28% and As by 112%,but not above the food safety criteria.