Abstract: OBJECTIVE To evaluate the value of cryptococcal capsular antigen test in early diagnosis of pulmonary cryptococcosis (PC) so as to raise the awareness of PC. METHODS The clinical data of 52 PC patients without HIV infection or organ transplantation who were pathologically diagnosed in the First Affiliated Hospital of Zhejiang University School of Medicine from Dec 2012 to Apr 2017 were retrospectively analyzed, the enrolled patients were divided into the antigen-positive group and the antigen-negative group according to the result of cryptococcal capsular polysaccharide antigen test, and a controlled analysis was performed. RESULTS Cough and expectoration, chest tightness, chest pain, blood-stained sputum and fever were the major clinical symptoms. Single or multiple nodules, lump shadow, infiltrating solid shadow and mixed lesions were the imaging manifestations. The patients who were tested positive for cryptococcal capsular polysaccharide antigen accounted for 63.46%(33/52), the positive rates of antigen of the patients with cough and expectation (24/32,75.0%,P=0.0288) and the patients with infiltrating solid shadow (19/24,79.17%,P=0.0295) were high, while the positive rate of antigen of the patients with nodules or lump was low. CONCLUSIONS It is difficult for the early diagnosis of PC due to the absence of specificity of clinical manifestations and imaging characteristics, the cryptococcal capsular polysaccharide antigen shows the advantages such as rapid, simple, non-invasive detection, high sensitivity and high specificity in the early diagnosis of PC.