The urban expansion-induced heat can deteriorate heat stress for urban dwellers, especially during heat waves. With a focus on the intra-urban variability of UHIs and thermal comfort, the urban parameterization within the CLM5 was modified to incorporate the LCZs framework to simulate urban climate during a HW event in the summer of 2013 in East China. The simulations were validated by observation data from a flux tower measurement site, conventional stations and automatic meteorological stations, which exhibits a reasonable agreement. The aim of this work was to investigate: 1) the variability of temperature and heat stress in relation to each urban LCZ, 2) the influence of intra-urban inhomogeneity on attributing factors of SUHII, 3) the response of CUHII and SUHII, urban thermal comfort and controlling factors of SUHII to HW. The results show that daytime and nighttime CUHII were highest in LCZ3 and LCZ1 areas, respectively. SUHII separately peaked in LCZ8 and LCZ1 areas during daytime and nighttime. Contrasts of CUHII and SUHII between urban classes could exceed 1.7℃ and 5.4℃ which varied with background climate and HW episode. Urban dwellers were exposed to the most serious heat stress in LCZ3 and LCZ1 areas over the north subtropical climate zone. The intra-urban heterogeneity resulted in the changes in dominant factors controlling SUHII that were modulated by local climate and HW intensity. Moreover, UHIs and thermal comfort were obviously affected by the occurrence of HW events such as the changes in CUHII for LCZ7 (1.0℃) and SUHII for LCZ8 (3.8℃).