Abstract: Pulmonary embolism has high incidence and mortality if treated improperly, but it was mistakenly diagnosed easily. So rapid and right diagnosis is crucial in successful treatment and gaining good prognosis. X-ray film is the necessary screening examination and UCG is useful in exclusion of heart disease. Radionuclide pulmonary perfusion and ventilation imaging is a traditional routine examination with high diagnostic accuracy. Spiral CT and MRI are excellent methods in diagnosis, treatment-directing and treatment effect-evaluating. However, the pulmonary angiography should be used if the diagnosis can not be confirmed with above mentioned noninvasive examinations.