Objective: To investigate the clinical and laboratorial characteristics of patients with myelodysplastic syndrome (MDS) and erythroid hyperplasia. Methods: MDS patients whose bone marrow was hypercellular with erythroid lineage more than 50% and blasts account for less than 20% of non-erythroid cells were enrolled in this study. The ratio of mature erythrocytes to nucleated erythrocytes was no more than 20, namely MDS patients with erythroid hyperplasia(MDS-E). The retrospective analysis comprised 102 patients with MDS-E from the First Affiliated Hospital of Suzhou University. Clinical characteristics, karyotype, and the prognostic significance of erythroid hyperplasia were evaluated. Results: A total of 48 MDS-E patients (47.1%) presented a variety of cytogenetic abnormalities. The most frequently involved chromosomes were chromosome 8 (39.5% of all abnormal karyotypes), chromosome 7 (22.9%), followed by chromosome 5 (18.8%), chromosome 1 (16.7%) and chromosome 20 (16.7%). Hemoglobin (Hb) level affected the prognosis by survival analysis. The overall survival (OS) of MDS-E patients with Hb equal or more than 70 g/L was longer than that of patients less than 70 g/L (P<0.001). Allogeneic hematopoietic stem cell transplantation (HSCT) significantly improved the OS compared with best supportive care (P<0.001) and chemotherapy (P<0.001). The extent of erythroid hyperplasia in bone marrow did not impact on prognosis (P=0.187). Conclusions: Compared with previous reports of MDS patients, MDS-E patients have higher level of erythroid hyperplasia, more common erythroid dyshematopoiesis, more frequent 8 and 1 chromosome abnormalities. The degree of erythroid hyperplasia is not correlated with prognosis. Allogeneic hematopoietic stem cell transplantation improves the prognosis.