This paper attempts to use timevarying parameter model to empirically explore the commodity price stability in the framework of nonlinear and disquilibrium cobweb model and takes pork price for example.The result shows that one of the judging theorem of commodity price stability in the frame of nonlinear and disquilibrium cobweb model,that is,the firstorder derivative of product price to its firstorder lag price is less than 1 constantly,could be used for empirical analysis by timevarying parameter model.And China’s pork price did not meet the stability condition,which results in the appearing of “pigcycle” repeatedly.Consequently,firstly,government should make policies to balance the high and low pork price and strengthen the support under the condition of low pork price in the market.Secondly,pork price index insurance shall be popularized to reduce the loss of pig breeding farmers when the pork price is low so that the supply of pork can be guaranteed.Finally,hog futures trading could be adopted to increase the importance of “expected price” in the production decision of pig breeding farmers.