Numerical analysis has been shown as an important tool in studying the dynamics of harmful algal blooms, exploring the causes, mechanism and prediction of red tides. In this paper, various multivariate statistical methods and biophysical models are reviewed in examining the roles of biological, chemical, physical factors and biological-physical interactions in red tides. These models have achieved some degrees of success in describing the underlying dynamical processes. However, relatively poor knowledge about physiological responses of bloom species to the physical field has greatly limited the predictive ability of existing models. The improvement of existing models will depend on a better understanding of the physical, physiological, and ecological processes and their interactions.