Infants are timid. When hearing strange sounds or seeing strange objects, or suddenly frightened, they fail to control their spirit and mind and develop into palpitation. Besides, the infantile external defending function is weak, exogenous pathogenic factors stay in the heart and impair the cardiac function of controlling mental activities, giving rise to palpitation. Also, the infantile spleen is often weak. Improper diet and excessive intake of uncooked, cold, fat and sweet food cause accumulated heat generating phlegm, which together with heat disturbs the heart, resulting in palpitation. Lastly, the congenitally weak and defective infants may suffer from impairment of the heart meridian. This may cause blood stasis due to qi stagnation, leading to palpitation.