The failure of injured axons to regenerate in the mature central nervous system (CNS) has devastating consequences for victims of spinal cord injury (SCI). Traditional strategies to treat spinal cord injured people by using drug therapy and assisting devices that can not help them to recover fully various vital functions of the spinal cord. Many researches have been focused on accomplishing re-growth and reconnection of the severed axons in the injured region. Using cell transplantation to promote neural survival or growth has had modest success in allowing injured neurons to re-grow through the area of the lesion. Strategies for successful regeneration will require tissue engineering approach. In order to persuade sufficient axons to regenerate across the lesion to bring back substantial neurological function, it is necessary to construct an efficient biocompatible bridge (cell-free or implanted with different cell lines as hybrid implant) through the injured area over which axons can grow. Therefore, in this paper, spinal cord and its injury, different strategies to help regeneration of an injured spinal cord are reviewed. In addition, different aspects of designing a biocompatible bridge and its applications and challenges surrounding these issues are also addressed. This knowledge is very important for the development and optimalization of therapies to repair the injured spinal cord.