The effects of shen xian sheng mai ye (SXSMY) on experimental sick sinus syndrome (SSS) were observed. By applying 20% formaldehyde to the rabbits' sino-atrial node area, we got the acute animal model of SSS. By observing the rabbits' heart rate (HR), arrhythmia and cardioelectric physiologic index in different periods, the results were as follows: (1) Increasing heart rate: SXSMY could increase rabbits' HR 10-30 times per minute by observing electrocardiogram within 2 hours (P less than 0.05-0.001). (2) Correcting arrhythmia: SXSMY could reduce arrhythmia of sinus nodal arrest and nodal rhythm remarkably. (3) Improving sinus atrial node function: SXSMY could improve sinus node recovery time (SNRT) and sinus atrial conducting time (SACT) with the method of atrial pacing (AP) (P less than 0.01-0.001). But the above results did not appear in atropine and glucose groups.