This study was focused on the evaluation of Nanjido landfill site by leachate analysis. Several parameters, for example pH, BOD, $COD_{Mn},;COD_{Cr}$, SS, TP, $NH_3-N$, Color, were selected as major leachate quality parameters. $BOD/COD_{Cr}$. was used to estimate the biodegradable portion in organic matter. Samples were collected at the leachate storage wells and leachate treatment facility inflow in each quarter of 2003. The results were as follows : 1. Inflow quality of treatment plant in 2003 was analysed as $pH;7.3~8.0,;BOD;12.4~30.0mg/L,;COD_{Mn};101.2~130.3mg/L,;COD_{Cr};122.5~238.0mg/L,;SS;16.1~115.3mg/L$, $T-P;0.27~0.80mg/L,;NH_3-N;208.0~~354.0mg/L$, Color $110.3~129.0$ unit. 2. $BOD/COD_{Cr}$ of inflow ranged between $0.07~0.16$ indicating that the landfill had the properties of old-fill and organic portion in leachate was mostly persistent organic matter. 3. Though concentrations of BOD, COD, $NH_3-N$, Color in leachate storage wells were mostly higher in first landfill than in second landfill, $BOD/COD_{Cr}$ ranging from 0.03 to 0.20, showed reversely. 4. Correlation coefficient$(R^2)$ between color and other parameters related to organic matter showed mostly above 0.7 and especially highest value with $COD_{Mn}$ of 0.7985.