On the basis of a thorough review of the up-to-date relevant literatures, the characteristics, material sources, and genetic mechanisms of carbonate cements in clastic reservoirs are systematically examined and discussed, the distribution laws under different mechanisms are summarized, and several issues that should be paid attention to are emphasized. Carbonate cements in clastic reservoirs are characterized by multiple mineral types, multiple formation phases and heterogeneous distribution. The material sources of carbonate cements include both endogenous and exogenous sources. Carbonate cements in clastic reservoirs can be formed by the synergistic diagenesis of sandstones and mudstones, evaporation, bioclast dissolution and re-precipitation, sedimentation rate controlling effect, thermal convection, deep hydrothermal fluid intrusion and other mechanisms. In the continental clastic reservoirs, the synergistic diagenesis of sandstones and mudstones is one of the most important mechanisms for the formation of carbonate cementation, but in marine-transitional strata, bioclastic dissolution and re-precipitation and sedimentation rate controlling effect are also important mechanisms for the formation of carbonate cementation. The mineral types and characteristics, controlling factors and distribution laws of carbonate cements under different mechanisms can vary significantly. Given the current status in carbonate cementation in clastic reservoirs, it is emphasized that particular attention needs to be paid to the uncertainty of the material sources proxied by δ13C value, the effect of high-frequency sequence stratigraphy and sedimentary environments on carbonate cementation in the transitional depositional settings and marine facies, and the non-unique interpretation of the origin of the same mineral type (such as "ankerite") or the same distribution (such as "top carbonate cementation layers") when it comes to determine the genesis of carbonate cements.