The electrophoretic mobilities (EPMs) of various leukocytes of mouse origin were measured using microcapillary electrophoresis (µCE) chips. The average EPMs of acute lymphoblastic leukemia (L1210), myeloma (PAI), myeloid leukemia (M1), and myelomonocytic leukemic (WEHI3) cell lines were −0.83×10 −4 , −1.0×10 −4 , −1.5×10 −4 , and −1.2×10 −4 cm 2 V -1 s -1 , respectively. The average EPMs of mouse primary blood leukocytes, bone marrow cells, and splenic cells were −2.0×10 −4 , −1.6×10 −4 , and −1.3×10 −4 cm 2 V -1 s -1 , respectively. EPM was different for each type of leukocyte. These quantitative data concerning cell surface charge are useful fundamental knowledge for understanding the interactions between cells and biomaterials, and for designing biomaterials.