This paper presents the first phase of a single tree model of the stock, respectively, cash bonds and bonds in the stock and cash combination of analysis, derived from the probability of the general formula and the value of the derived formula combination. N phase and then an analysis of the binary tree, consider the n-1 times from a node into two nodes n times in the last bifurcation of any one look at their respective separate into a single binary tree, first calculate the time n the value of the claim, and the price of tree to use its process of development plans and portfolio value function, the introduction of N-1 times the value, and so on, from each layer can be introduced in front of the value of a layer of nodes, and use of its move gradually from the value derived from the principles of options, the last available single binary tree root value。