The proposed research is concerned with the development and application of statistical mechanical theories for assemblies of amphiphilic molecules in solution. The fundamental analysis of the competition between hydrophobic and hyprophilic solvation in these systems seems central to understanding biochemical phenomena, and the ultimate goal of the work proposed here is to understand the structure and dynamics of biomolecules. To reach this end, two general classes of systems will be considered: micelles and proteins. For the former, the objective is to begin with relatively realistic intermolecular potential models and to arrive at theoretical predictions of thermodynamic and structural properties of aqueous surfactant assemblies. For the latter, the objective is to derive a systematic microscopic basis for the virtual bond formulation and related simplifications of protein modeling, and to apply such a formulation to study the folding process and ultimate structures of biopolymers in solution. Recent advances in liquid state integral equation theories and their connection with stochastic field theoretic descriptions of solvation, and the current technology of computational devices are all significant, since they allow for the correct molecular formulation of solvent induced and mediated interactions. The proposed research will utilize the methods of field theory along with Monte Carlo and stochastic molecular dynamics computer simulations.