Software framework to support modeling and performing simulations of multilevel physiological systems has been developed and expanded to support the cloud computing. The framework is composed of two blocks, i.e. PhysioDesigner and Flint. PhysioDesigner is an application providing a graphical user interface for assisting users in multilevel modeling of physiological functions and a terminal interface for script-based model building. Models built on PhysioDesigner are written in PHML (the physiological hierarchy markup language). Flint is a standalone simulator, supporting MPI for parallel computing on a proper system environment. Based on the standalone application, Flint K3 system supporting cloud computing has been developed, which provides a solution for portable high performance simulation. At the website of Flint K3, users can upload models described in PHML. In addition, PhysioDesigner and other applications can submit simulation jobs to Flint K3 directly at online.