Abstract: The paper introduce the theory and methods of log-constrained impedance inversion based on constrained sparse spike inversion (CSSI). On the assumption that the reflection coefficients of formation are sparse, CSSI can be used in high resolution 3D wave impedance inversion under the constraints of geology-model and log data. As an example, it is showed that the approach has effects on reservoir tracing and characterization in Canxue field, the East China Sea.