In this study, an experimental and analytical study on adsorption and adsorption kinetics of organic matters in titanium oxide (TiO2, Degussa P25) with synthetic wastewater was investigated. In order to understand the removal of different organic sizes in detail molecular weight (MW) distribution of organics matters was examined in terms of number and weight-average MW. The large MW (33950 dalton) of synthetic organic matters (SOMs) was significantly removed by TiO2 adsorption and the slight decrease of the small MW (970 dalton) occurred with time. A characterization method was applied to evaluate the composition of SOMs in terms of adsorbability by adsorption of TiO2. Several adsorption equilibrium and batch kinetics experiments were conducted with different initial concentrations of SOMs and different amounts of adsorbent. A binomial distribution(s) of SOM fraction with the Freundlich coefficient (k) was obtained. The synthetic wastewater was explained by a finite number of pseudospecies (N) identified with a Freundlich isotherm constant (k) value. These parameters were determined by the characterization procedure, together with ideal adsorbed solution theory (IAST) with the pseudospecies number method. Prediction of adsorption isotherm and kinetics derived from a binomial concentration distribution of the characterization procedure were in good agreement with experimental data conducted.