Objective To study the influence of E2F1 gene knockout on the Hematopoietic stem cells and progenitor cells. Methods Cells from the peripheral blood, spleen and bone marrow of E2F1 knockout and wildtype mice were stained with kinds of antibodies, and analyzed by flow cytometry. Results Compared with wildtype mice, significant differences were found in the peripheral blood and bone marrow, pre B cell, myeloid progenitor cell and Hematopoietic stem cell in the E2F1 nockout mice. No. of Hematopoietic stem cell and progenitor cell decreased, and percent of G1 stage Hematopoietic stem cell decreased. Conclusion Hematopoietic stem cell and progenitor cell decreased in E2F1 gene knockout mice.