Objective：This study aims to screen some effective indicator to foretell the extent of atrial fibrosis in patients with sick sinus syndrome（SSS）. Methods：Total 95 patients were 40-80 years old，who were consecutively enrolled in cardiovascular department of the Affiliated Jiangning Hospital of Nanjing Medical University from January 2017 to January 2018，and were divided into two groups. One group is control，another group is patients who were diagnosed as SSS. All the patients received echo-cardiogram and dynamic electrocardiogram examination. And transforming growth factor-beta 1（TGF-β1），N-terminal pro-brain natriuretic peptide（NT-proBNP），propeptide of type Ⅰ procollagen（PINP），procollagen Ⅲ N-terminal propeptide（PⅢNP） in the blood of these patients were also measured. Besides，the amplitude of P wave in lead Ⅱ were measured in electrocardiogram of every patient. Then，differences in all parameters between the two groups were compared. Results：There were no statistical differences in age，sex，uric acid，blood glucose and diameter of left or right atrial between two groups，but the amplitude of P wave in electrocardiogram of SSS group was significantly lower than that of control group［（0.09±0.01）cm vs.（0.15±0.02）cm，P=0.001］. The levels of TGF-β（P=0.002），PⅢNP（P=0.017），NT-proBNP（P=0.001） in SSS group obviously higher than those in control group. Besides，after one year’s follow-up，the variation of TGF-β1，PⅢNP，NT-proBNP and the amplitude of P wave in lead Ⅱ between SSS and healthy control group has statistical significance. Conclusion：The levels of TGF-β1，PⅢNP，NT-proBNP in serum and the amplitude of P wave in electrocardiography can predict the morbidity and development of SSS