A bilateral spared dorsal root ganglion model was established in healthy adult cats by bilateral resection of L1-5 and L7-S2 dorsal root ganglia. L6 dorsal root ganglia were spared. Zusanli (ST36) and Xuanzhong (BL39) or Futu (ST32) and Sanyinjiao (SP6) were altatively electro-stimulated on the right leg. Immunohistochemical staining of anti-serum platelet-derived growth factor demonstrated that the number of total neurons and medium-small sized platelet-derived growth factor positive neurons was significantly decreased on the 7th day following injury. After 7 days of acupuncture, the total number of positive and large neurons staining for platelet-derived growth factor on the acupuncture side significantly increased compared to the non-acupuncture side. After acupuncture for 14 days, the total positive and medium-small sized neurons significantly increased compared with the non-acupuncture side. Results indicate that acupuncture promoted the synthesis of platelet-derived growth factor in spared dorsal root ganglia.