An approach to measuring technological change is presented and applied to evaluating technological benefits of the HPPSARP

(High Performance Propulsion System Advanced Research Program)which comprises 72 projects relating to 228 technical feature aspects. The technological changes in theoretical and experimental aspects are illustrated. Technological gaps between Chinese and international advanced levels and relative technological change rates are analyzed. The analysis shows that the technological benefits of the program raise the state-of-the-art of China's aeroengine in the 228 technical aspects and reduce the technological gaps by 1.6 year. Moreover

the relative technological change rate is estimated to be up to 1.225.