The oral route of drug delivery is most preferred route of drug delivery due to its various advantages like patient compliance, ease of administration. But it has some drawbacks like non site specificity. To overcome this drawback gastroretentive drug delivery system is used. To understand various physiological difficulties to achieve gastric retention, we have summarized important factors controlling gastric retention. This review also includes different approaches for Gastroretentive drug delivery system i.e. floating drug dosage systems, swelling or expanding systems, high density system, mucoadhesive systems, Magnetic systems, raft forming system, evaluation tests, advantages, disadvantages, future prospects, different marketed preparations.