Controlled release matrix tablets of theophylline were prepared with hydrophilic polymer xanthan gum and evaluated. Controlled release matrix tablets of theophylline were prepared by wet granulation technique by varying polymer ratios (1:1 and 1:2) and hardness (5, 6 and 7 kg/cm2). Tablets were prepared by wet granulation technique. The granules are subjected for preformulation studies. Compressed tablets were evaluated for hardness, uniformity of weight, friability, drug content, thickness and diameter. All the formulation showed compliance with pharmacopoeial standards. IR spectroscopy revealed that there was no interaction between the drug and the polymer used in the formulation. In vitro dissolution studies were performed using Disso 2000 (paddle type). Among all formulations F6 showed controlled 73.18 + 1.55 % after 10 hr. The kinetic treatment showed that the drug release followed higuchi model. F-6 formulation was subjected to stability studies at three different temperatures for 6months period. It was found to be stable. From this study it was proved that the release of theophylline from matrix tablets was influenced by both polymer ratio and hardness.