Objective To study the change and relationship among thrombopoietin (TPO), platelet parameter and megakaryocyte in immune vasculitis of weanling rabbits. The role of platelet parameter, megakaryocyte, thrombopoietin (TPO) in kawasaki disease (KD) was accessed. Methods An experimental model of weanling rabbits for KD was reproduced by bovine serum. The blood platelet counts (PLT), mean platelet volume (MPV), platelet distribution width (PDW), platelet hematocrit (PCT), megakaryocyte and TPO were determined ev-ery four days. Pathological analysis of coronary artery, liver, spleen, kidney, brain was also done. Results PLT, PCT, PDW and the per-centage of total number of megakaryocyte and middle board megakaryocyte in the experimental group had obviously changes at the 12th, 16th, 20th, 24th, 28th day (P <0.05). MPV in the experimental group had obviously changes in the 12th, 24th, 28th day(P <0.05). TPO in the experimental group was higher than that in control group (P < 0.05). TPO in both groups was positively correlated with PLT, PCT, the percentage of total number of megakaryocyte and middle board megakaryocyte (P < 0.05). In experimental group, small arteries showed obvious inflammatory injury at the 17th day, medium-sized arteries showed obvious inflammatory injury at the 28th day, but the aortas showed mild changes. Conclusion Platelet, megakaryocyte and TPO took part in the pathogenesis of KD, and they had interaction and co-ordination in the course of regulation, which suggested that they could be used to monitor the changes in the KD and guide the treatment.