The new generation of oral controlled release drug delivery system technologies brings valuable benefits to patients. Oral route is the most convenient and commonly route of drug delivery. Oral controlled release formulations are designed to deliver a drug at a pre determined rate by achieving a constant drug level for a specified period of time with lower side effects. Controlled release drug delivery have become a significant priority worldwide, it may be possible to achieve rapid absorption of drug and increased bio availability, reduced toxicity and improved patient compliance. This article mainly focuses the requirement of controlled drug delivery system, their advantages, disadvantages, formulation, various methods and use of controlled release system.