Objective:To investigate the incidence of chronotropic incompetence(CI) in a cohort of sinus bradycardia and the value of CI between exercise test(ET) and Holter monitoring electrocardiogram(Holter). Methods:Sixty-seven subjects of sinus bradycardia(48 male and 19 female,the mean age of 46.7 ± 13.9 years) and 47 control subjects of normal heart rate(34 male and 13 female, the mean age of 48.4 ± 7.6 years) received treadmill exercise test and Holter detection. The maximal heart rate during ET and Holter were observed. CI was defined as the failure to achieve 85% of the age predicted maximal heart rate(APMHR) during ET or failure to 100bpm during Holter. Results:①Sixteen sinus bradycardia subjects(23.88%) and 4 normal control subjects(8.51%) than 85% of APMHR(P < 0.05). ②The prevalence of CI achieved less diagnosed by ET was 23.88% and 7.46% diagnosed by Holter in the subjects of sinus bradycardia(P < 0.05). Conclusion:The population with sinus bradycardia has a higher incidence of chronotropic incompetence. ET is a more valuable diagnostic technique to CI than Holter.