Abstract: Objective To investigate the effect of early ventilator therapy on pulmonary circulation function and Syndecan-1 level in patients with acute respiratory distress syndrome(ARDS). Methods Totally 80 patients with ARDS were selected and divided into control group and observation group according to different therapeutic plans, with 40 cases in each group. All patients were treated with conventional symptomatic treatment. The control group was given conventional ventilator treatment, and the observation group was given synchronous early ventilator treatment. The clinical effect was compared between the two groups. Pulmonary circulation indexes ［pulmonary circulation resistance(PVR), extravascular lung water(EVLW), mean pulmonary artery pressure(MPAP), right ventricular stroke work index(RVSWI)］, blood gas indexes including arterial partial pressure of oxygen ［p_a(O₂)］, arterial partial pressure of carbon dioxide ［p_a(CO₂)］, oxygenation index ［p_a(O₂)/FiO₂］, blood oxygen saturation(SaO₂), procalcitonin(PCT), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), neutrophil elastase(NE)and Syndecan-1 were compared between two groups. Incidence of - complications and score of Acute Physiology and Chronic Health Evaluation Ⅱ(APACHE Ⅱ)were compared between the two groups. Results After treatment, the levels of PVR, EVLW and MPAP in the observation group were significantly higher than those in the control group, while the RVSWI level in the observation group was significantly lower than that in the control group(P<0.05). After treatment, the levels of p_a(O₂), p_a(O₂)/FiO₂ and SaO₂ in the observation group were significantly higher than those in the control group, while the p_a(CO₂)level was significantly lower than the control group(P<0.05). After treatment, the levels of PCT, IL-18, TNF-α, NE and Syndecan-1 in the observation group were significantly lower than those in the control group(P<0.05). The incidence of complications in the observation group was 17.50%, which was significantly lower than 42.50% in the control group(P<0.05). After treatment, the score of APACHE Ⅱ in the observation group was(12.01±3.12)points, which was significantly lower than(17.29±3.48)points in the control group(P<0.05). Conclusion For patients with ARDS, early application of ventilator therapy can effectively reduce the incidence of ventilator-related complications, inhibit inflammatory reactions and improve pulmonary circulation function.