Credit risk management is an integral part of banking business. By modifying the standard Markowitz model, the paper aims to study optimum credit portfolio with binary variable, which decides whether providing loads. The model can evaluate the cumulative risk and returns by considering the asset correlation and whether providing loads in the prospective of influencing risk indicators and profit rates. It enforces the empirical research of optimum portfolio by using the proposed model in this paper and the statistics offered by Standard & Poor's rating agency.

Credit rating is a comprehensive evaluation of the capability and the integrity of fulfilling economic commitments for the individual, the economy and financial instrument. The main function of credit rating lies in the credit risks revealment, which plays an irreplaceable role in increasing the efficiency of financial market. It is of great significance for the security of national finance and economy to have a proper credit rating. Different levels and time of default probability will be studied in this paper, which also includes further discussion on the risk premium and associated dependencies.

In order to analyze and study our country’s real estate price’s and food price’s effects on inflation, the article chooses relevant statistics recorded from the first Quarter in 2000 to the fourth Quarter in 2010, and carries out the empirical test on the basis of the VAR model. As the result shows , inflation has a longterm and stable cointegration relationship with both the real estate price and the food price, besides, the increase of which are contributive to the occurrence of inflation. By comparison, however,the rise of the real estate price contributes more to the inflation, while the influence on inflation caused by the food price increasing last even longer.

Embedding and extracting algorithm for watermarking in the frequency domain based on the Fresnel and Fourier Hologram was proposed. The image watermarking was restored from the JPEG images with different compression ratios and the stability of watermarking image was compared between two different transformations. The result show that the image watermarking obtained by the proposed algorithm had perfect imperceptibility and stability. By comparison, however, the one based on the Fresnel Hologram had superiority in terms of stability.