  Based on the q-exponential distribution which has been observed in more and
more physical systems, the varentropy method is used to derive the uncertainty
measure of such an abnormal distribution function. The uncertainty measure
obtained here can be considered as a new entropic form for the abnormal
physical systems with complex interaction. The entropy obtained here also
presents non-additive property for two independent subsystems and it will tend
to the Boltzmann-Gibbs entropy when the nonextensive parameter q->1. It is very
important to find that for different systems with any q, this entropic form is
always concave and the systemic entropy is maximizable.
