Objective: To investigate the levels of cytokines related to T-helper (Th) 17 cells in serum and signal transducers in the psoriatic lesions of patients with psoriasis vulgaris of blood-heat syndrome (BHS) and blood-stasis syndrome (BSS). Methods: Sixty patients with psoriasis vulgaris were divided into the BHS and BSS groups according to the syndrome differentiation of Chinese medicine (CM). Ten healthy subjects were considered as the control group. Cytokine levels of interleukin (IL)-17, IL-23 and IL-6 in serum were determined by enzyme-linked immunosorbent assay. Expression levels of signal transducer and activator of transcription 3 (STAT3), p38-mitogen-activated protein kinase (MAPK) and STAT6 in the psoriatic lesions were determined using immunohistochemistry (IHC), Western blot, and real-time quantitative reverse transcription polymerase chain reaction, respectively. Results: Production of IL-17, IL-23 and IL-6 in the BHS group and BSS group were significantly increased compared with those in the control group (P〈0.05). Levels of IL-17 and IL-23 in the BHS group were higher than those in the BSS group (P〈0.05). Compared with the control group, IHC positive expressions and protein expressions of STAT3 and p38-MAPK, and the STAT3 mRNA expressions in the BHS and BSS groups were significantly higher (P〈0.05 or P〈0.01). The protein expression of STAT3 in the BHS group was significantly higher than that in the BSS group (P〈0.05). Conclusions: Cytokines in serum and signal transducers in the psoriatic lesions alter with various CM syndromes of psoriasis. The results provide scientific basis for the treatment based on syndrome differentiation of CM in treating psoriasis vulgaris.