Objective To study the characteristics of microenvironmental flow and the process of macromolecular drug delivery in solid tumor. Method3D models simulating tumor hemodynamics and drug delivery were developed. Microcirculation and concentration distribution of two macromolecular drugs in tumor were simulated. ResultsThe model successfully reflected abnormal tumor hemodynamics, which results in impeded drug delivery and uneven concentration distribution of the drug. The results also shows that the drug with lower molecular weight is more easy to spread in tumor and excrete with interstitial fluid flow. In contrast, the drug with higher molecular weight tends to accumulate and maintain an effective concentration in tumor for a longer period. ConclusionsThe results derive from this model can reflect physiological conditions, providing a reliable numerical model for the investigation of tumor microenvironment, drug delivery and strategy of therapy.