This paper theoretically and numerically investigated a novel evaluating standard delta(e) for the enhancement of convective heat transfer based on the entransy theory. In the theoretical derivation, the differential equations about entransy are established using the method of micro-control volume which can give the obvious physical changing processes. And then, an efficiency factor delta(e), is recommended according to physical mechanisms of entransy dissipation which is considered the impact of energy dissipation. The principle is verified by numerical simulation. The results indicated that delta(e) is more appropriate for evaluating the ability of convective heat transfer enhancement comparing with the traditional method of FSP (field synergy principle) and EDEP (entransy dissipation extremum principle). The results also showed that the higher the factor of delta(e), the more efficient heat transfer process. (C) 2016 Elsevier Ltd. All rights reserved.