This paper develops a new event-triggering approach for a class of nonlinear systems. This approach goes beyond the control of certain systems by developing sporadic feedback control laws to solve unstructured uncertainty problem. It guarantees asymptotic stability of a broad range of uncertain systems under sample and hold implementation while it efficiently reduces the communication samples. Under the proposed scheme, in order to handle the uncertain dynamics, the sampling time might become smaller than that in the approach of the certain systems. Using linear matrix inequalities, the controller gains and the event triggering parameters are obtained simultaneously. In addition to addressing new scheme for uncertain systems, we propose another triggering mechanism for affine nonlinear systems. Simulation results illustrate that the increase of triggered messages due to the nonlinearity and uncertainty is kept small enough that can be neglected when compared with conventional event-triggering policy.