To develop sustained release matrix tablet of Tramadol HCl that deliver drug for 24 hr and to be taken once in a day. Drug having high solubility and relatively shorter half-life suggests its suitability for an extended formulation. If it is formulated by conventional tablets, it will require multiple daily administrations which ultimately results into inconveniency to the patients and possibility of reduced compliance with prescribed therapy. Also fluctuation in plasma drug concentration leads to exaggerated side effects, this all limitations can be minimized by adopting extended release formulation. To reduce the frequency of administration and to improve the patient compliance, Once in a day sustained release formulation is desirable. It describes the influence of the concentration of HPMC K4M, HPMC K15M and HPMC K100M on Tramadol HCl sustained release formulations using box-behnken design.These Polymers were selected as an independent variables. Drug release after 8 hr, 12 hr and 16 hr were selected as a dependent variables. Optimized formulation found by similarity and dissimilarity factor follow zero order kinetic with non-fickian diffusion as a drug release mechanism.