The oxidation of total organic content (TOC) present in the two selected Bangalore city lake (Medahalli and Ulsoor lakes) water samples at two different seasons of the year 2010 using photocatalyst TiO2 as been studied. The different forms of TiO2 such as natase, rutile and mixed form(Degussa P25) are used for the study. Themixed form(mixture of natase and rutile) has given better results in photooxidation than the individual TiO2 forms. The oxidation of these pollutants present in the wastewater will be oxidized by photo/ photocatalysis and the extent of contamination and oxidation are measured by COD and BOD tests. The photooxidation studies were made under natural sun light illumination. The efficiency and the rate constants for the oxidation of TOC are calculated and presented. The TOC oxidation reactions are found to follow first order kinetics. The rate constants for photocatalytic oxidation of TOC of theMedahalli lake samples of June and Decembermonths are 0.333 and 0.49 (x 10-4 s-1) and for Ulsoor lake samples are 0.52 and 0.666 (x 10-4 s-1) respectively.