Inclusion Criteria:  Sign the informed consent form before the trial, fully understand the content, process and possible adverse reactions of the test; Able to complete the study according to the requirements of protocol; Aged between 18 and 65 years old, both men and women; For healthy subjects: Male ≥50kg, female ≥45kg,body mass index(BMI)=weight (kg)/height 2 (m2), BMI is 18-28 kg/m2 (including the critical value); For patients: BMI is 18-28 kg/m2 (including the critical value), and body weight is ≥45kg. For healthy subjects: normal or abnormal vital signs, physical examination, laboratory examination, electrocardiogram, and imageological examination have no clinical significance; For healthy subjects: FEV1 and forced vital capacity(FVC) are at least 90% of the predicted values; Subjects (including male subjects) have no pregnancy plan and have voluntarily taken effective contraceptive measures for at least 1 month after being screened to the last use of the study drug; For patients: Vital signs range: systolic blood pressure 90 to 140mmHg, diastolic blood pressure 50 to 90 mmHg, heart rate 50 to 90 bpm; For patients: 12-lead electrocardiogram with QT interval corrected ≤450 msec (males) or ≤470 msec (females), QRS interval ≤120 msec, PR interval ≤200 msec and no morphologic and other clinical significant abnormalities (such as left band branch block, atrioventricular node dysfunction, ischemic ST segment abnormalities); For patients: Ability to perform acceptable and reproducible spirometry; For patients: According to the diagnostic criteria of 2018 Practical Edition of Guidelines for the Diagnosis and Treatment of COPD, the patient was diagnosed with COPD for at least 1 year;Post-bronchodilator spirometry at screening must demonstrate FEV1/FVC ratio of ≤0.70 and FEV1 must be ≥40 % to ≤80% of predicted normal; For patients: mMRC Scoring at screening ≥2; For patients: Clinically stable COPD in the previous 4 weeks; For patients: Capable of withdrawing long acting bronchodilators until the end of the treatment period, and short acting bronchodilators for 8 hours prior to administration of study medication; For patients: Current and former smokers with a smoking history of ≥10 pack years（smoking at least 20 cigarettes a day for 10 years or at least 10 cigarettes a day for 20 years）; For patients: beta agonists are currently used only "when needed"; For patients: Never smoked or An ex-smoker for ≥6 months；  Exclusion Criteria:  Preexisting or existing the neuropsychiatric system, respiratory system, cardiovascular system, digestive system, hemo-lymphatic system, immune system, liver and kidney dysfunction, endocrine system, musculoskeletal system, or other disease that the investigator assesses that may affect drug metabolism or safety. For healthy subjects: Have a history of fainting needles, fainting blood. For healthy subjects: Known allergy to the study drug and their metabolites or any of the excipients of the formulation. For healthy subjects: Those who smoked more than 5 cigarettes per day during the 3 months before the trial. A history of alcohol abuse in the past 6 months (14 units of alcohol consumed per week: 1 unit =360 ml of beer or 45 ml of 40% alcohol spirits or 150 ml of wine). For healthy subjects: Donated blood or had substantial loss of blood (more than 400 mL) within 2 months before the test. For healthy subjects: Had taken any prescription, over-the-counter, vitamin product or herbal medicine within 1 month prior to the use of the study drug. Participated in other clinical trials within 3 months prior to this study. Positive for hepatitis (including hepatitis B and C), human immunodeficiency virus（HIV） or syphilis at screening. Women who are pregnant or breast-feeding. Positive test for alcohol. For healthy subjects: Blood collection is difficult or cannot tolerate venipuncture blood collection. For healthy subjects: The subject is unable or can not comply with ward management regulations. For healthy subjects: The subject is unable to complete the study due to personal reasons. For healthy subjects: Any circumstances that the investigator considers to pose a safety risk to the subject during the study or may interfere with the conduct of the study. For patients: Intolerance to salbutamol, tiotropium, or this product or prior exposure to Ensifentrine (RPL554). For patients: Use of any medicine within 4 weeks prior to initiation of the study drug, including non-prescription medications and herbs, except vitamins. For patients: Physical examination findings that researchers consider clinically significant at the time of screening. For patients: A history of cardiovascular disease (including arrhythmias) or active hyperthyroidism. For patients: History of malignancy of any organ system, treated or untreated within the past 5 years, with the exception of localised basal cell carcinoma of the skin.