Given that there is very limited knowledge about how urban thermal environment varies diurnally,we first classified Local Climate Zones (LCZs) based on multi-source remote sensing data such as airborne LiDAR and IKONOS-2,and then investigated the responses of LCZs to diurnal Land Surface Temperature (LST).The results suggested that there was significant diurnal variability in LST among LCZs.During the daytime,the warmest and coolest zones were large low-rise buildings (LCZ 8) and water (LCZ G),respectively.At night,bare soil or sand (LCZ F) obtained the lowest LST,while the warmest zone was water (LCZ G).With the increasing of building height,daytime LST related to compact and open built-up types tended to decrease,and an opposite trend was observed at night.LCZs were differentiated better at night than during daytime.Moreover,regardless of day and night,open high-rise built-type (LCZ 4) and LCZ G were the most differentiated zones for built-up and land cover types,respectively.