Root exudation plays an important role in maintaining plant growth and mediating the cycling of soil C-nutrient, in spite of that the current studies of root exudation C input flux and the influencing factors of root exudation C input flux mainly focus on the growing seasons. On the other hand, many studies of root exudation C input flux ignore the overall evaluation of root exudates throughout the year. In order to enrich the overall study of carbon input in root exudates throughout the year, we took the root exudation of Cupressus funebris and Pinus massoniana Lamb in hilly areas of central Sichuan as research objects. And we collected the root exudation of Cupressus funebris and Pinus massoniana Lamb in situ in January (winter), April (spring), August (summer) and October (autumn) of 2021, respectively. And furthermore, we also collected and analyzed climate data and root characteristics data simultaneously. The results were as follows: 1) The root exudation rates of Cupressus funebris Endl and Pinus massoniana Lamb showed a similar seasonal variation pattern. It is to say that the root exudate rates of two tree species increased first and then decreased, and also root exudate rates reached the highest in summer and reached the lowest in winter. 2) The seasonal variation patterns of fine root biomass and fine root root vitality were consistent with the rate of root exudations. It is to say that both of fine root biomass and fine root vitality of Cupressus funebris Endl and Pinus massoniana Lamb increased first and then decreased, with the highest value in summer and the lowest value in winter. 3) The root exudation rate and root characteristics (including fine root biomass and root vitality) of Cupressus funebris Endl and Pinus massoniana Lamb were significantly positively correlated with temperature and precipitation. In addition, the root exudation rates of two species were also significantly positively correlated with their own root vitality. The above results indicated that the rate of root exudation had an obvious seasonal variation pattern. And furthermore, the seasonal variation pattern was also strongly influenced by the change of root vitality under seasonal climate change. Therefore, gaining a comprehensive understanding of the seasonal variations in root exudates is essential for accurately evaluating the input flux root exudates in forest ecosystems. And more importantly, in-depth exploration of the seasonal changes of root exudates can also enrich our knowledge of the seasonal dynamic changes in root exudates and their regulatory factors in forests.