To describe the clinical and subclinical characteristics of interstitial lung disease related to some connective tissue disease. Research object and method: Retrospective and prospective cross-sectional description of 102 patients diagnosed with interstitial lung disease with connective tissue disease at the Respiratory Center of Bach Mai Hospital from 1/2021 to 8/2022. The mean age was 57.29±11.55 years old, over 55 years old (65.7%), of which female accounted for 69.6%, the female/male ratio was 2.29/1. Shortness of breath (90.2%) and Coughing up phlegm (44.1%) are the most common symptoms. Rale explosion (85.3%) is the most common physical symptom in the lung. The most common non-respiratory physical symptom was Arthralgia (48%). Anemia accounts for 44.1%, mainly isochromic anemia (39.2%), the average hemoglobin concentration is 121.64±19,735 g/l. The average CK value was 323±603.89 U/L, 27 cases increased CK (30.34%). The mean RF value was 36,773±74.99 IU/mL, in 30 cases increased RF (37.04%). The mean CRP hs concentration was 6.352±7,723 mg/dl. The mean ferritin concentration was 1401±1588 ng/ml. Pulmonary arterial pressure had an average value of 40.32±17,358 mmHg higher than normal, mainly a slight increase in pulmonary artery pressure (61.2%). The mean %FVC compared with the theoretical value is 60.71±15,437, which is lower than normal, mainly due to restrictive ventilation disorder (80%). The most common lesions on baseline HRCT were opacities (69.6%) and traction bronchiectasis (52.9%). The most common lesion morphology was OP (21.6%) and NSIP (19.6%) with the characteristics of bilateral distribution, predominance of the peripheral, lower lobes of the lung. The most common connective tissue disease is Polymyositis/Dermatomyositis (39.3%), followed by Scleroderma (20.6%), Qverlapping Syndrome and Mixed Connective Tissue (20.6%), accounting for the proportion lower than that of Systemic Lupus and Rheumatoid Arthritis.