To discuss the cause of positive atropine test and the possible reason for false positive atropine test, providing a certain aids for clinical diagnosis and treatment. Eighty patients, conducted atropine test due to sinus bradycardia, with positive results from January 2010 to June 2013, were selected. Sinus heart rate were calculated and the changes in heart rhythm were observed by tracing electrocardiogram. Esophageal electrophysiological examination and atropine test were administrated. SPSS 10.0 statistical software was adopted and x² test was applied for comparison. The positive results of atropine test and results of esophageal electrophysiological examination in different ages showed that as age grows, false positive rate of atropine test was significantly reduced, presenting statistically significant difference (x² =6.2821, P<0.05); The positive results of atropine test and results of esophageal electrophysiological examination in different heart rates showed that false positive rate of atropine test on those with bradycardia was smaller than those with significant bradycardia, presenting statistically significant difference (x² =5.1792, P<0.05). Simple sinus bradycardia is mostly caused by the increase of vagus nerve tension, almost negative in atropine test. Sick sinus syndrome (SSS) leads to abnormity in pacemaking and conduction induced by organic lesions in sinus nodes. Moreover, as the disease progresses, it is able to cause severe and persistent sinus bradycardia, almost positive in atropine test. Therefore, to identify the increase in vagus nerve tension or sinus bradycardia induced by SSS has a crucial clinical significance. Furthermore, the false positive and false negative profiles in atropine test can easily lead to misdiagnosis and mistreatment in clinic.