In order to understand the differences in daily activity, we monitored red deer (Cervus alashanicus) and blue sheep (Pseudois nayaur) from October 2014 to October 2015 using camera-traps in the Helan mountains. Through the "overlap" statistical package in R, we used the kernel density estimation and coefficient of overlap to analyse the relevant monitoring data. The results showed that red deer had crepuscular habits (peak period:5:00-10:00, 16:00-21:00). However, this changed seasonally (daily activity pattern coefficient of overlap Δ=0.77). From the warm season to the cold season, peak moved towards noon (warm season:4:00-8:00, 16:00-22:00; cold season:6:00-11:00, 15:00-20:00). Daytime activity intensity in the cold season was greater than that in the warm season, but was lower at night time than that in the warm season. The daily activity patterns of blue sheep showed mainly daytime activity, reaching peak periods from 8:00 to 10:00 and from 13:00 to 15:00. However, this changed seasonally (daily activity pattern coefficient of overlap Δ=0.74). From the warm season to the cold season, the peak backward (warm season:7:00-9:00, 12:00-14:00; cold season:9:00-11:00, 13:00-17:00), and night activities decreased. The activity patterns of both species showed similarities in that their daily activity pattern was higher (Δ=0.67) and a seasonal change occurred from the cold to the warm season (cold season:Δ=0.66; warm season:Δ=0.61). The characteristics of the two species' daily activity patterns are as follows:red deer showed crepuscular habits, and blue sheep showed a daytime activity pattern. The former has a lower daytime activity than that of the latter but is stronger than the latter at night, and the activities of the two species are generally staggered at the peak hour. These results not only improve clarity on the daily activity patterns of red deer and blue sheep, but also analyses the competition between species distributed in the same domain from a temporal perspective and provide the necessary scientific basis for further behavioural ecology research.