Objective To investigate and compare the effects of sustained inflation (SI) and pressure controlled ventilation (PCV) on lung recruitment in patients with ARDS, and on hemodynamics and respiratory mechanics of patients. Methods Ten patients with ARDS were included in this randomized clinical trial ( RCT), and SI (40 cmH20, 40s) and PCV (20 cmH20, 2 min) were successively applied to each patient under sedation, non-muscle relaxation state. There was a elution period between two types of recruitment maneuver (RM). Parameters of respiratory mechanics, gas exchange and hemodynamics were measured before RM (T0), 5 min after RM (T2) and one hour after RM (T3). Parameters of respiratory mechanics and hemodynamics were measured during the period of RM (Tl). Results (1) The PaO2 at T2 and T3 increased significantly in comparison with that at To ( P < 0.05), and there was no significant difference in PaO2 between two types of RM (P > 0.05). There were no significant differences in PaCO2 between two types of RM at each interval (P > 0.05). (2) The cardiac index ( CI) at T1 decreased significantly compared with that at To in two types of RM (P < 0.05), but there was difference in CI between two types of RM (P > 0.05). There were no differences in MAP and HR at these intervals (P > 0.05). (3) The functional residual capacity (FRC) at T2 and T3 increased significantly in comparison with that at To in two types of RM (P < 0.05). The static compliance (Cs) at T1 improved significantly (P < 0.05), but there was no difference in Cs between two types of RM ( P > 0.05). There was no difference in plateau pressure (Pplat) at all intervals (P >0.05). Conclusions The oxygenation, FRC, and Cs improve significantly in both SI-RM and PCV-RM, and the effects of two types of RM are similar. The SI-RM and PCV-RM have the similar impact on circulatory system during RM.