Objective:To explore the morbidity and risk factors of de novo malignancy after heart transplantation (HT).Methods:From June 2004 to August 2021, 995 patients undergoing HT were selected and followed up.The epidemiological characteristics, the morbidity of de novo malignancy (DNM) and its risk factors were examined.Kaplan-Meier survival analysis was performed for calculating the cumulative incidence and mortality of DNM.Log rank test was utilized for comparing the survival rate of each subgroup.Cox regression model was employed for examining the relationship between the included factors and the endpoint of DNM.Results:The median follow-up period was 6.36(3.64, 10.18) years.Thirty-six patients (3.6%) developed DNM during follow-up.Lung cancer accounted for 22.2%(8/36) of DNM while digestive system tumors accounted for 38.9% (including gastric cancer 6/36, 16.7%; liver cancer 3/36, 8.3%; colon cancer 2/36, 5.6%). The cumulative morbidity of DNM at Year 1/5/10/15 post-HT was 0.1%, 2.3%, 4.9% and 7.6% respectively.The median survival time of DNM recipients was 83.32 months.The mean survival time was significantly lower than those without DNM[(115.32±13.12) vs.(194.22±2.58), P<0.001]. The mortality of DNM recipients was around 6.57 folds higher ( HR=6.57, 95% CI: 4.06-10.64, P<0.01). Age was an independent risk factor for an occurrence of DNM.Hypertension and diabetes were also correlated with DNM. Conclusions:DNM after HT is associated with shorter survival time.And age is an independent risk factor for DNM after HT.