The pulpal or periapical diseases of immature permanent teeth often lead to incomplete root development. It is a challenge for us to figure out how to ensure the continuous growth of the teeth and the formation of roots. There are many cases about pulp regeneration reported recently. With the regeneration and differentiation ability of stem cells, which exist in residual pulp tissue, periapical and periodontal tissues, the regeneration of new vital pulp tissue was induced under proper conditions, which is highly vascularized and rich in connective tissue, thus prompting continuous root growth and development, increasing root length, thickening root canal walls, and facilitating the coarctation of the apical foramen. Besides, clinical and radiographic examinations shows successful results about the regenerative treatment, which is of milestone significance. The pulp regeneration treatment is designed to replace the pathological dental pulp tissue with new regenerated pulp tissue, based on biological tissue engineering process. This process includes two key parts: one is pulp revascularization, regenerating new vital pulp tissue in the root canal to achieve the continuous root growth and development; the other is tissue engineering, new pulp dentin complex is regenerated by the stem cells under the induction of suitable biological active scaffolds and growth factors. This article reviews about the research progress and clinical characteristics of aforementioned two key parts.