The present study deals with the mechanisms for the hot-spot formation and pressure wave development associated with end-gas autoignition during knocking combustion of n-heptane/air mixture. The discussion is based on a one-dimensional (1-D) direct numerical simulation, where the compressible Navier-Stokes equations are solved with a detailed chemical kinetic mechanism of n-heptane, involving 373 species and 1071 reactions. The result demonstrates that the first trigger for a hot-spot formation is a compression wave generated by forced autoignition of a hot kernel and its reflection at a wall. The wall reflection of the propagating compression wave periodically produces an instantaneous temperature increase, which leads to the production of a larger amount of chemical species compared to that of other end-gas points. This non-uniform progress of chemical reaction process continues to exist at the wall, although the temperature increase is transient, resulting in faster autoignition and pressure wave generation at the wall. Thus, an important aspect of observing chemistry behaviors rather than temperature is demonstrated on the mechanism of hot-spot formation. The present study further addresses the reactivity of hot-spots on the relevance to pressure wave developments, wherein a zero-dimensional (0-D) ignition problem with pulsed compression waves is introduced. The higher reactivity of n-heptane/air mixture against pulse waves is observed with the faster ignition delay times in lower and higher initial temperature conditions. Conversely, the result at initial temperatures of 750-800 K indicates the lower reactivity with no significant effects of pulse waves on the ignition delay times. This is connected with the fuel characteristics of a negative temperature coefficient. Thus, in the 1-D simulations, a hot-spot with the high reactivity enhances spatial temperature difference in the end-gas region, leading to strong pressure wave generations. In contrast, a hot-spot with the low reactivity suppresses the pressure wave development with little spatial variation in temperature. The result demonstrates a significant aspect of hot-spot formation and reactivity on pressure wave development during knocking combustion. (C) 2017 The Combustion Institute. Published by Elsevier Inc. All rights reserved.