Objective To study the effect of ghost red blood cells (GRBCs) on white blood cell (WBC)-mediated adhesion of tumor cells (TCs) on endothelial cells (ECs) in shear flow. Methods GRBCs with hematocrit (Hct) of 20% were added in the parallel plate flow chamber to observe changes in the number of tethered WBCs on ECs, the collision between TCs and adhesive WBCs, and the number of firmly adhered TCs at different shear rates of 62.5, 100, 200 s-1, respectively. Results GRBCs could increase the number of adhered WBCs on ECs and the collision between TCs and adhesive WBCs, and finally enhance the adhesion of TCs on ECs, especially at high shear rate (200 s-1). However, the adhesion efficiency of TCs was not significantly influenced by GRBCs. Conclusions GRBCs in shear flow can promote TC adhesion on ECs, and the research finding will provide a theoretical basis for cancer therapy.