Abstract: 20 cases of hamartomas （15 pulmonary,1 intratracheal,2 gastric and 2 duodenal） have been admitted in this hospital since 1965.All these were identified by histopathol- ogical examination.The history,X-ray and pathological findings of 4 cases （2 gastroin- testinal and 2 other types） are reported here. Hamartoma may be single and multiple.There was generally no subjective symp- tom in patients with pulmonary hamartoma,which was found incidentally on X-ray ex- amination of the chest during check-up.Therefore,maybe fluroscopy or roentgenography of the lung is the only way to discover this type of tumor. Some cases in this series were misdiagnosed as gastric or pulmonary carcinomata, and one case of duodenal hamartoma co-existed with pulmonary carcinoma was discove- red on postmortal examination. Moreover,clinical features,differential diagnosis,Pathological and X-ray character- istics of hamartoma are discussed in this article.