The invention provides a zwitterionic-bias material for blood cell selection, being a copolymer formed by zwitterionic structural units and charged structural units wherein the zwitterionic structural unit comprises at least one positive moiety and one negative moiety, a distance between the positive moiety and the negative moiety is a length of 1~5 carbon-carbon bonds, and the zwitterionic structural units and charged structural units are randomly arranged to have zwitterionic-bias.本發明提供一種雙離子電荷偏差型血球篩選用材料,其係雙離子構造單元以及帶電荷構造單元所構成的共聚物,其中雙離子構造單元至少包括一帶正電基團與一帶負電基團,該帶正電基團與該帶負電基團的距離為1~5個碳碳鍵的長度,該帶電荷構造單元與該雙離子構造單元無規則排列而構成一雙離子電荷偏差。
