加权法在建立灰色模型GM（1，1）中的理论分析和实际应用

For letting up the calculated error of the Gray model, Improve the calculation accuracy of the gray model. Method: make use of the weighted average to proceed the mathematical analysis simulate to the accumulated generating an ordered of numbers, so it can acquire the gray model time function of the different, To the smallest residual sum of squares as the standard, to optimize the time function.Result: Compared with traditional method, the new one can let up the error sum of squares, clearly raise model accuracy.Conclusion: The weightd model may application in tendency forecast of the viral hepatitis incidence rate.