Hydrogel is a creative polymeric biomaterial which can resemble extracellular matrix (ECM) in vitro. Hydrogel is also a material with intrinsic bioinert, but it can offer mechanical support and developmental guide for cell growth and new tissue organization by designing physicochemical and biological properties of hydrogels precisely. This review mainly introduces design of hydrogels, properties and applications in tissue engineering and regenerative medicine, drug delivery, stem cell culture and cell therapy.