Objective To observe the clinical curative effect of enteral nutrition (EN) liquid rich in omega-3 polyunsaturated fatty acids (ω-3PUFA) for patients suffering from acute respiratory distress syndrome (ARDS) and treated with mechanical ventilation.Methods A prospective study was conducted, 40 patients with ARDS admitted and treated in the intensive care unit (ICU) and respiratory department in the Traditional Chinese Medicine Hospital of Huzhou from May 2007 to October 2016 were enrolled, and they were randomly divided into a study group and a control group, each group 20 cases. The same heat EN support of different prescriptions was given respectively in the two groups, nasal feeding with EN emulsion rich in ω-3PUFA (TPF-T) was applied in the study group, while in the control group, nasal feeding with EN suspension liquid of protein fiber type (TPF) was given, and the target energy established for the two groups was 104.0 - 125.5 kJ·kg-1·d-1. In the two groups, before and after treatment for 7 days, the changes of nutrition indexes [total protein (TP), albumin (ALB)], inflammatory index [C-reactive protein (CRP)], immune indexes (T cell subgroup CD4, CD8 and CD4/CD8), blood gas analysis indexes [arterial blood oxygen partial pressure (PaO2), oxygenation index (PaO2/FiO2)] and mechanical ventilation time, the length of stay in ICU and fatality rate were observed; the occurrences of false aspiration, feeding tube obstruction, high blood sugar, excessive water, diarrhea, constipation, etc. complications related to the process of the treatment were observed in the two groups. Results After treatment, the levels of TP, ALB, CD4, CD4/CD8, PaO2, PaO2/FiO2 in two groups were higher than those before treatment, the levels of CRP and CD8 were lower than those before treatment, and the improvement degrees of indexes in study group were superior to those in the control group [TP (g/L): 59.9±4.8 vs. 58.6±4.1, ALB (g/L): 31.9±3.4 vs. 31.1±4.4, CRP (mg/L): 25.8±18.5 vs. 38.1±24.9, CD4: 0.30±0.05 vs. 0.28±0.04, CD8: 0.21±0.03 vs. 0.19±0.04, CD4/CD8: 1.57±0.39 vs. 1.55±0.42, PaO2 (mmHg, 1 mmHg = 0.133 kPa): 152.7±15.8 vs. 140.6±22.2, PaO2/FiO2 (mmHg): 304.5±32.1 vs. 280.2±44.1]; the survival patient mechanical ventilation time (days: 7.1±2.2 vs. 9.2±3.5) and length of stay in ICU (days: 10.4±2.8 vs. 12.6±3.6) were significantly shorter in study group than those in control group (allP < 0.05), and fatality rate was 15.0%in both groups.Conclusion The EN liquid rich in ω-3PUFA is more beneficial to the recovery of respiratory function than EN of protein fiber type in patients with ARDS, and the former EN also can shorten the mechanical ventilation time and the length of stay in ICU.