Based on the Markowitz portfolio theory, an investment preferred curve is proposed and an approach to determining the optimal portfolio of a specific investor is designed by using the preferrd curve as its tool.

On the aspect of OECD countries and emerging market countries,this paper analyses the pension funds\' investment preferences of localization and its causes in OECD countries.

This article proposes a curve,which is called investing preferred curve,to compensate the shortage of the traditional theory,and further analyzes and studies the movement and property of the asset combination curve and the variation law of individual portfolio and the inner mechanism on the basis of the preferred curve discussed in the first section.

By analyzing the financing problem of small&medium-sized firms,it is believed that the financing problem ties up with the conflict between firms preference for equity financing and individual s preference for debt financing.