Abstract: In order to make accurate and scientific performance evaluation and maintenance decision of asphalt pavement,the pavement condition index( PCI) detection data of asphalt pavement of Beijing expressways in different years was investigated and analyzed in this paper. The PCI decay trend was studied and an exponential type prediction model of PCI under different maintenance mode was summarized. Result shows that the maintenance type and intensity is different at different ages of expressways. PCI of expressways may decrease in a low intensity manner or in a wave shaped high intensity manner under different maintenance modes. When the age of expressway approaches its severing life the PCI shows a sharp decay trend. In Beijing area,the value of pavement factor “a”is between0. 008 ~ 0. 035. Prediction result of PCI presented in this paper is more accurate and accords with the asphalt pavement PCI decay trend of expressways and maintenance manner. The result of this paper provides a theoretical support for the accurate prediction of PCI and maintenance decision of expressway pavement.