1. Study type: This is a randomized, parallel controlled and single blind study. The sample ratio of the experimental group and the control group will be 1:1.
2. Study Setting and Recruitment: All participants experience vaginal delivery and are diagnosed with mild postpartum anemia. They will be recruited from the obstetric inpatient department in two hospitals: the first affiliated hospital of Guangzhou University of Traditional Chinese Medicine, and Maternal and Child Health Hospital of Panyu District in Guangzhou City. All assessments and interventions will occur at hospitals.
3. Randomization, blinded method, and allocation concealment: Patients meeting the criteria were randomized into experimental group or control group, according to a computer-generated list. The patients in experimental group will receive the treatment of Ejiao compound while the patients in control group will be treated by Polysaccharide iron complex. The study physicians will receive a sealed decoding envelope per treatment, they will not know the identity of the participants, will not handle the study products, will not know the assigned treatment, and will not share their own examination results. After receiving the evaluation by the study physicians and finishing the investigation form, the patient will take her own sealed decoding envelope and go to the pharmacy of the clinical trial center to receive her medication. The staff of the pharmacy of the clinical trial center is responsible for the distribution and return of experimental drugs to patients. All envelopes, sealed or unsealed, will be returned to the investigators at the end of the study. Patients would be required to return boxes whether they are used and unused at each visit and compliance will be assessed by counting the bottles and capsules.
4. Sample size calculation: It was reported that treatment with oral iron for anemia in postpartum women increase the Hb concentration by 49.3% by day 40. Combined with etiological treatment, Ejiao compound used to treat anemia in non pregnant population for three months, the Hb concentration increased by 66.9%. Basing on the results of literatures mentioned above, the investigators suppose that the difference of Hb concentration between patients only receiving the Ejiao compound for 4 weeks and patients only receiving oral iron for 4 weeks would be 25.0%. The α-value is set at 0.05 and the test power is 0.90. The final sample size should be 68 in each group. With an anticipated dropout rate of 20% during the follow-up, the initial sample size for each group should be 85, and 170 in total for two groups.
5. Statistical analysis: The statisticians will be blinded to the allocation of the participants. Statistics Package for Social Science (SPSS)19.0 statistical software packages will be used to analyze the data. The intention-to-treat population will include all randomized patients who receive the assigned treatment at least once, and who have an evaluation of outcomes. The measurement data will be analyzed by using t-test or the rank sum test, and the numeration data will be analyzed by using chi-square test or Fisher's exact test. P\<0.05 indicates statistical significance.