Chronic disease prevention is a very important public health problem in China，in which traditional Chinese medicine has its unique advantage.This article analyzed the dosage of Chinese herb and its therapeutic characteristics from aspects of chronic disease always companied with deficiency，and tending to cause long course and complications.The necessity and possibility of theoretical construction for rational dosage of prescriptions and herbs were also put forward.The study on Chinese herb dosage for chronic disease and treatment models will be constructive and significant in building dosage theory of Chinese herb and guiding the treatment for chronic disease.