Blood supply is believed to be an important aspect in the development of pathological scars. However, there are controversies about vascular distribution, vascular structure and blood flow in pathological scars. Additionally, hypoxic microenvironment plays an important role in the vascularization of pathological scar tissues, and hypoxic conditions can be reflected by metabolic indexes and some cytokines. Furthermore, the correlation between blood supply and tissue hypoxia is controversial. The aim of this article is to review the literature on the characteristics of blood supply and tissue hypoxia in pathological scars, from which we can see pathological scars have unique characteristics of blood supply that are closely associated with tissue hypoxia. Moreover, development in the treatment of pathological scars is herein reviewed.Chin Med Sci J 2017; 32(2):113-118. DOI:10.24920/J1001-9294.2017.014 ATHOLOGICAL scars include hypertrophic scar and keloid. They influence appearance and even cause functional disturbance, and place tremendous physiological and psychological burdens on patients. Therefore, pathological scars have been a challenge in plastic surgery and the focus of research.Blood supply is believed to be an important aspect in the development of pathological scars, and has thus attracted more attentions in recent years. However, there are controversies about blood supply in pathological scars.Hereby we summarized the advances of research on the blood supply in pathological scars, and explored future research directions. The vascular structure of pathological scars has different manifestations between hypertrophic scars and keloids. In terms of spatial vascular structure, blood vessels within hypertrophic scar tissues have a structure perpendicular to the skin surface, whereas those within keloid tissues present a typical dispersed, extended vascular structure. VASCULARITY OF PATHOLOGICAL SCARS 5,6The diameter or patency of the blood vessels of pathological scar remains controversial. Thaís et al used stereological methods to obtain information on pathological scar tissues with a microscope, and proposed that the blood vessels within the pathological scars were dilated compared with those in normal skin and normal scars.