Water contaminated or changed their properties partially or entirely as a result of household, industrial, agricultural and other uses is called as wastewater. The analysis used to determine the characteristics of the wastewater are those of quantitative chemical instead of those of qualitative biological or physical. These are Biochemical Oxygen Demand test (BOD5, Chemical Oxygen Demand test (COD), Total Organic Carbon Content test (TOC) and Dissolved Oxygen (DO). In this study, BOD curves were generated for the particular reaction conditions and the effects of reaction rate constant on these curves were studied firstly. This is foreseen regarding the reaction kinetics. Secondly, the correlations among the results of BOD, COD, TOC and DO tests in determining the quality of water resources were searched, and it was seen that finding a correlation among these tests results would be impossible directly but some correlations could be done among the results of these tests applying for the same sample diluted in different rate. However, these correlations could not show on-line changes exactly among their relationships.