The　Intra-Aorta　Pump　is　a　novel　VAD　assisting　the　native　heart　without　percutaneous　drive-lines　or　cannula.　To　predict　the　pressure　drop　and　blood　flow　along　with　the　change　of　pump　speed,　a　nonlinear　model　has　been　made.　An　Intra-Aorta　Pump　was　run　at　speed　of　5400RPM　and　exert　a　blood　flow　of　2　similar　to　5　L/min.　Compare　with　the　experimental　data,　the　error　of　the　prediction　is　lest　than　15%,　the　experimental　results　showed　that　the　model　can　predict　the　change　of　pressure　head　and　fluid　flow.