This paper gives a positive deviation and negative deviation to measure risk-return and risk-loss,and gives an information k to measure frequency about risk-return and risk-loss;It′ ll transform the models to a more simple model.

The absolute-deviation is defined as variance.

Portfolio choice model based on mean absolute deviation and it s simulated annealing algorithm;

Using the absolute deviation as a risk measurement index,a novel absolute deviation optimal purchasing portfolio model for multiple markets is built in risk minimization target.

This paper provides a mean absolute deviation protfolio selection model on account of return data, the model uses mean absolute deviation as measure of the risk and gains a optimal portfolio in possesing taxes and transaction costs by solving the linear programming.

Using Skewness and Kurtosis to adjust critical number of firm s credit grade migration,using Semivariance Absolute Deviation method to measure loan portfolio risks,a portfolio optimization model of banking asset based on the adjusted credit grade and the semivariance absolute deviation is set up.