Based on the traveling wave theory, a nonlinear discrete map of a transmission line system terminated by an N-channel metal oxide semiconductor (NMOS) inverter is established. After simulating by the nonlinear discrete map, it is found that the change of the reflection coefficient may lead to spatiotemporal bifurcation and chaos, and that the initial distribution significantly affects the spatiotemporal pattern of steady state. For the zero initial distribution, the spatiotemporal pattern is very regular, whereas the complex spatiotemporal pattern may appear when the initial distribution is nonzero. The analysis results demonstrate that the complex spatiotemporal behaviors originate from the infinite-dimensional essence of the transmission line and the nonlinear voltage-ampere characteristics of the NMOS inverter.