The experiment was investigated the ability of the natural sedimentation to reduce amount of organic compound in household wastewater including removal mechanisms of organic compound in household wastewater by sedimentation. Sedimentation used in this experiment were collected from klongpremprachakon in 2 locate are as follows; in front of Watsamiannari and in front of train station Bangkhen. The experimental sediment bring it from area actual and sediment has autoclaved for analysis organic compound included BOD value COD value and organic matter by variation of time testing 3 5 12 and 24 hour respectively. The research result found that the experimental 24 hour Amount of organic compound in terms of BOD COD concentration and organic matter retained in household wastewater quite low. The natural sediment redound to adsorption and biodegradation by microorganism was reduce amount organic compound included BOD value COD value and organic matter better than inactivated sedimentation by autoclave.