This thesis reviews some theories in the book [D01] such as the single-period asset pricing theory and H-J-M model. The aim of this thesis is to give some brief but clear explanation to asset pricing in the financial markets and a stochastic partial differential equation for forward-rate. It concludes the following two parts: (a) In single-period model, the state-price is the key of assets pricing. (b) Forward rate process is completely determined by associated instantaneous volatility based on the H-J-M model. We give some new proofs for some lemmas, propositions, corollaries and theorems in book [D01].