Theophylline is used to treat lung disease and COPD (Bronchitis, emphysema). Etophylline is derivative of Theophylline, used as anti-asthmatic agent. It is adenosine antagonist that relaxes muscles of bronchi. They are under the class of drug Xanthine. These medicines need to be used regularly for relief of asthmatic symptoms. Various analytical methods are reported for estimation and stability of Theophylline and Etophylline in bulk and in different Formulation. A comprehensive Literature review is prepared for Theophylline and Etophylline.