Abstract: Taking the leachate in Lhasa landfill as the research object， the indexes of pH、CODCr、BOD5、NH3-N、chroma、SS、As、Cr6+、TN、TP、fecal coliform group number of leachate samples before and after treated by leachate treatment station in different seasons were analyzed and evaluated， respectively. The results showed that the average concentrations of CODCr、BOD5、NH3-N、Cr6+、As、TP and TN in the leachate from Lhasa landfill reached 2.01×104、4.24×103、726.09 、0.28、0.11、16.92、730.33 mg/L， respectively. Moreover， the changes of seasons had a great influence on the concentration of CODCr、BOD5、NH3-N and TN in the leachate. The concentration of CODCr and BOD5 was lower than the average concentration of leachate water quality in China’s early landfill， but higher than that of leachate water quality in China’s old landfill. After treated by leachate treatment station， the concentration of each pollutant in the water from discharge port  could reach the limit of water pollution concentration of domestic waste landfill  in Standard for Pollution Control on the Landfill Site of Municipal Solid Waste（GB 16889—2008）， and the overall effluent quality could meet the water quality standards for urban greening.