Third order nonlinear optical properties of a series of 5 dioxonaphthothiazole compounds were studied with three dimensional degenerate four wave mixing. The third order nonlinear optical susceptibilities |χ (3) | and the third order hyperpolarizabilities γ of dioxonaphthothiazole compounds were measured to be 4.3×10 -13 esu and 4.4×10 -31 esu respectively. The influence of the molecular structure upon the third order nonlinear properties of the materials was analyzed.