Economic systems may not evolve evenly in calendar time． So come economic time and time de-formation． Although subordination is the most important mathematical method for time deformation，there is a deficiency in the definition． Because it requires that the stochastic time process and the latent process should be independent． It’s constraining in practice，because the processes often correlate in this way or that way． In order to model such cases，a new concept of dependent-subordination is proposed here． It generalizes subordination from independence to dependence and can be applied in many circumstances，for example，it can be ap-plied to prices and volumes． In early studies，researchers always choose volume as a stochastic time for price． But now we know that price isn’t independent of volume and they are correlated． So，choosing volume as a stochastic time for price isn’t appropriate in subordination． But，with the definition of dependent-subordina-tion，volume can be a stochastic time for price． This coincides with the idea that price changes may really be driven by volumes． Next，diffusion properties of dependent-subordination are presented． Finally，assets pri-cing under economic time is discussed as an application of dependent-subordination． Results are similar to ordinary calendar ones of CAPM and APT．