The aim of tissue engineering is to develop cell, construct, and living system technologies to restore the structures and functions of damaged or degenerated tissues. Surgical strategies that have evolved to deal with tissue loss include organ transplantation from one individual to another, tissue transfer from a healthy site to an affected site in the same individual, and replacement of tissue functions with synthetic material devices. All of these strategies have limitations. Organ transplantation is not always feasible as the number of organ donors is far less than the number of patients waiting for organ transplantation. The complications of immuno-suppressive agents are also trouble for the organ recipients. Tissue engineering (TE) seeks to provide a new solution to tissue loss. Scaffolds with porous microstructures are commonly used in TE. This chapter reviews and reports the TE strategy, requirements of scaffolds in TE, as well as different biomaterials that are often used to fabricate tissue engineering scaffolds.