This is a multisite, double-blind, randomized, placebo-controlled, and parallel study designed to evaluate the clinical efficacy and safety of Huaiqihuang granule for treatment to children with chronic primary immune thrombocytopenia (Qi Yin deficiency).

The randomized clinical trial included subjects (n =216) will be randomly divided into experimental (n = 162) and control groups (n =54) according to a random number table. Patients in the experimental group will receive Huaiqihuang Granule . Patients in the control group will receive placebo a placebo-controlled designed is used for this study. To minimize the risks, treatment stopping rules and subsequent measures are established for subjects whose disease under study become worsening during the study. Subjects receiving placebo treatment will switch to investigational drug after Week 24 to reduce the risk of lack of efficacy by placebo.

The primary outcome measures is proportion of patients whose hemorrhage has improved (clinical effective rate).

Inclusion Criteria:

1. Male or female, aged between 1 and 14 years (inclusive) ;
2. Is diagnosed as immune thrombocytopenia according to the criteria of ICD-10, i.e., platelet < 100×109/L for at least two hematology tests with normal blood cell morphology; skin petechia, ecchymosis and (or) the clinical manifestations of mucosa and visceral hemorrhage; no splenomegaly; exclusion of other secondary thrombocytopenia, such as aplastic leukemia, aplastic anemia characterized by thrombocytopenia as the first hematologic abnormality, hereditary thrombocytopenia, thrombocytopenia secondary to other autoimmune diseases, infections or drugs etc...
3. Meet the diagnosis criteria for Qi Yin deficiency in traditional Chinese medicine;
4. Time since initial diagnosis of ITP until randomization is at least 12 month, i.e., course of disease ≥1 year;
5. Values of prothrombin time (PT/INR) and activated partial thromboplastin time (aPTT) are within 1.2 times of normal reference range;
6. Values of biochemistry parameters including creatinine, ALT, AST, glucose, total bilirubin are less than 1.2 time of the corresponding upper limit of normal range;
7. Has signed and dated the informed consent in volunteer by the subject and the subject's legal guardian(s) (for subject who is less than 8 years old, the informed consent will be signed and dated by the subject's legal guardian(s) in volunteer).

Exclusion Criteria:

1. Is diagnosed as congenital thrombocytopenia;
2. Is diagnosed as secondary thrombocytopenia;
3. Is diagnosed as non-immune thrombocytopenia;
4. Has medical history of diabetes;
5. In the judgement of Investigator, the subject is not appropriate to participate in this study.