[Objectives] Mammals play a crucial role as foundational elements of ecosystems, with their diversity and structure forming the basis of ecosystem functionality. In this study, we analyzed the current status of species diversity, distribution characteristics, and structure of forest-dwelling mammals in the Tangjiahe area of the Giant Panda National Park, Sichuan. We compiled data from 215 infrared-triggered cameras deployed in forest habitats to conduct a preliminary analysis of the altitudinal and seasonal variations in the activity of forest-dwelling species. In addition, we examined the altitudinal distribution and daily activity patterns of the five ungulate species with the highest relative abundance index.Our primary goals included updating species diversity and investigating spatiotemporal distribution patterns which had not been previously reported. [Methods] Data were collected from 215 camera traps deployed in forest habitats ranging from 1 210 to 2 694 m above sea level in the Tangjiahe area of the Giant Panda National Park (Fig. 1). The relative abundance index (RAI, IRA), Shannon-Wiener index (H′), and Pielou’s evenness index (J) were calculated for different altitudinal ranges and seasons. The Kruskal-Wallis test, ANOVA, or t-test were selected based on the normality test for significance analysis. Spearman’s correlation coefficient was calculated between the relative abundance index of five dominant ungulate species and altitude. Daily activity patterns were analyzed using kernel density estimation. All analyses and chart creation were completed using Excel, R 4.2.1, ArcGIS 10.8, and Origin 2022. [Results] The total monitoring effort amounted to 47 196 camera-days, resulting in 73 635 independent photographs. We identified 22 mammal species belonging to 4 orders and 12 families, comprising 3 Primate species, 4 Rodentia species, 8 Carnivora species and 7 Artiodactyla species (Table 1). Among these mammals, 5 species were classified as Class I and 8 species as Class II key protected wildlife in China. Reeves’ Muntjac Muntiacus reevesi, Wild Boar Sus scrofa, Takin Budorcas taxicolor, Chinese Goral Naemorhedus griseus, Tibetan Macaque Macaca thibetana were the 5 most abundant mammal species. Our findings revealed the following characteristics regarding forest mammal diversity in Tangjiahe:(1) The relative abundance index (RAI, IRA) in the high-elevation band (2 101﹣2 700 m, IRA = 570.5 ± 199.5) was significantly lower than that of low-elevation band (1 200﹣1 600 m, IRA = 1 223.8 ± 1 017.8) and middle-elevation band (1 601﹣2 100 m，IRA = 1 355.1 ± 785.1) (Fig. 2). The Shannon-Wiener index and the Pielou’s index were highest at middle elevation band (J = 0.74, H′ = 2.17), and decreased sequentially in low-elevation band (J = 0.60, H′ = 1.82) and high-elevation band (J = 0.59，H′ = 1.77) (Table 2). (2) The species richness in winter (IRA = 936.1 ± 809.6) and spring (IRA = 870.5 ± 598.6) was significantly lower than that in autumn (IRA = 1 366.7 ± 1 087.9, P < 0.05). There were no significant differences in species richness between summer (IRA = 1 178.3 ± 1 032.2) and autumn, spring, or winter (Fig. 3). (3) The Pielou’s index is the highest in summer (J = 0.69), followed by autumn (J = 0.67) and spring (J = 0.67), and is the lowest in winter (J = 0.66). The Shannon-Wiener index was highest in autumn (H′ = 2.05), followed by summer (H′ = 2.03), with the lowest values in spring (H′ = 2.00) and winter (H′ = 2.00) (Table 3). The correlations of relative abundance with altitude for five ungulate species were as follows:Reeves’ Muntjac (ρ =﹣0.6), Wild Boar (ρ =﹣0.25), and Chinese Goral (ρ =﹣0.35) showed a negative correlation with altitude, while Takin (ρ = 0.48) and Tufted Deer Elaphodus cephalophus (ρ = 0.31) showed positive correlations. The relative abundance of the Reeves’ Muntjac was highest at an elevation range of 1 400﹣1 600 m (IRA = 1 318.6 ± 795.4). Wild Boars (IRA = 1 046.5 ± 748.2) and Chinese Goral (IRA = 280.9 ± 117.6) also had the highest relative abundance at 1 400﹣1 600 m. The highest relative abundance for Tufted Deer was found at an elevation range of 1 800﹣2 000 m (IRA = 131.6 ± 85.7). Takin had the highest relative abundance at an elevation range of 2 600﹣2 800 m (IRA = 384.6 ± 123.3). (4) Except for Wild Boar, all species exhibited a bimodal activity pattern, with peaks occurring during dawn and dusk. The peak activity times were 7:00﹣9:00 and 17:00﹣19:00, with a trough from 12:00﹣14:00 (Fig. 5). Significant differences (P < 0.05) were found in the diurnal activity rhythms between the Tufted Deer and the Reeves’ Muntjac, as well as between the Tufted Deer and the Takin. The Wild Boar exhibited a unimodal activity pattern with peak activity from 17:00﹣19:00. [Conclusion] This study shows that making full use of mammal diversity monitoring data can effectively identify species of concern in regional biodiversity inventories, contributing to more objective biodiversity assessments and enabling management agencies to better target conservation and management issues.