The development of washingmachines production has been so rapid that 8 830 000 sets were produced in 1985, 2000 times as many sets as produced in 1978. How about the future development? By our mathematics model, we can forecast the washingmachine demands in the future years and that the mature period of the life periodic curve for washingmachine products is from August, 1983 to January, 1991. The model can be also used to forecast the products of other durable consumer goods.