Ascaris larvae or eggs can be found in sputum is the clinical symptom of pulmonary ascariasis, ascaris larvae or eggs can be found in sputum examination. After human accidentally swallowing the eggs of infected Ascaris lumbricoides, they hatch in the small intestine, and the Ascaris larvae break out of their shells and reach the lungs. When the Ascaris larvae migrate in the lungs, they may damage the pulmonary capillaries and alveoli causing punctate hemorrhagic alveoli, fine bronchitis and increased mucus secretion of eosinophil infiltration or the formation of eosinophilic granuloma. The adult worms may occasionally enter the thoracic cavity through the liver to the lung, or penetrate into the venous system through the right heart to the lung, or through the pharynx, trachea and bronchi to the lung, causing lung abscess, pulmonary embolism or asphyxia. Diagnosis of pulmonary ascariasis: The main symptoms are chills, fever, chest tightness, itchy throat, dry cough, urticaria, and in a few patients, symptoms of toxic encephalopathy such as asthma, dyspnea, blood in sputum, chest pain, headache, convulsions, and coma. Signs are often absent or there are scattered dry and wet rales in both lungs, and those with toxic encephalopathy may have pupil changes, positive Bartholomew’s sign and Kirsch’s sign. Laboratory tests may show an increase in peripheral blood eosinophils in the early stage of acute mass infection with Ascaris larvae, generally up to 20%-70%, and Ascaris larvae or eggs may be found in sputum. x-ray chest radiographs show scattered, dotted, flocculent or small fuzzy marginal shadows in the lungs. According to the comprehensive analysis of epidemiology, clinical manifestations and laboratory tests, but Ascaris infection is still mainly diagnosed by parasitology.