This study discussed the appropriateness of organic matter indexes such as biochemical oxygen demand(BOD) and chemical oxygen demand with potassium permanganate(COD_(Mn)) in water quality environmental standard of streams and lakes and the applicability of the items to water quality environmental standard to add or substitute COD with potassium dichromate (COD_(Cr)) and total organic carbon(TOC) being used as index of organic matter. And indexes of organic matter content and organic carbon concentration were distinguished between dissolved and particulate component in water sample to estimate their effect on pollutants loading in lake and stream. The ratio of COD_(Cr)/BOD was 5.1 under BOD concentration 3㎎/L in river water quality environmental standard II, and 2.67 above it. This ratio was diminished to 2.04 when BOD concentration was more than 8㎎/L, in river quality environmental standard IV. Also the ratio of COD_(Mn)/BOD showed 2.16 under 3㎎/L(BOD), and 1.1 above it. This ratio is also diminished to 0.84 over 8㎎/L(BOD). Accordingly, we should apply this ratio depending on the concentration level to add and change organic matter index of water quality environmental standard newly. The ratio COD_(Cr)/COD_(Mn) both in lake and stream shows 2.37(r=0.986, p<0.001). But the ratios showed range of 2.34∼2.50, which is no much difference of this ratio according to COD_(Mn) concentration.