Part I. Dilute Solutions. Chapter 1. Some Fundamentals. Chain models. Basic assumptions and approximations. Distribution functions. References. Chapter 2. Two-Parameter Theory. Chain dimensions. Second virial coefficient. Steady transport coefficients. References. Chapter 3. Renormalization Group Theory. Basic ideas and formulation. First-order theory. Theory of Douglas and Freed. References. Chapter 4. Some Recent Topics. Theory of Weill and des Cloizeaux. Coil-globule transition. Characteristic frequency. Macrorings. Appendix. References. Chapter 5. Stiff Chains. Introduction. Theories for unperturbed wormlike chains. Experimental data and comparison with theory. Excluded-volume effects on chain dimensions. Optical Anisotropy. Helical wormlike chains. Appendix. References. Part II. Concentrated Solutions. Chapter 6. Basic Concepts. Concentration regimes. Correlation length. Effects of concentration. Appendix. References. Chapter 7. Semi-dilute Solutions. Static properties. Transport coefficients. Other theories. Appendix. References. Chapter 8. Polymer Self-Diffusion. Definitions and basic relations. Theoretical aspects. Typical experimental results. Computer simulations. Viscosity. References. Chapter 9. Phase Equilibria. Thermodynamic relations. Binary solutions. Quasi-binary solutions. Remarks. Appendix. References. Chapter 10. Some Other Topics. Ring polymers. Spinodal decomposition. References. Subject Index.