Abstract: The current study investigated the napping patterns and the effects of napping on nighttime sleep quality and daytime functioning in different regions of China. A total of 3, 320 samples from 31 provinces, municipalities, and autonomous regions were included through an online survey. The results showed that the proportion of the population who have napping habits was commonly high in each region, with a higher proportion in Southern China and Southwestern China, and a relatively lower proportion in Northeastern and Northern China. In addition, stable napping habits contributed significantly to improving subjective daytime functioning and nighttime sleep quality. However, an excessively long nap might lead to a decrease in nighttime sleep quality. Furthermore, the onset time of napping significantly predicted individuals' daytime functioning, and individuals who started napping between 13:00 and 14:00 reported their best performance during daytime. The present findings not only suggest rationalizing individuals' nap schedules but also provide evidence to further pay more attention to napping.