Abstract: To study the stoichiometric relationships of C, N, P, and K in Cypress plantations in different regions of the hilly areas of central Sichuan, and to explore the impact of regional differences on nutrient cycling in Cypress plantations, as well as to understand the distribution of nutrient elements in various organs of Cypress plantations and the condition of nutrient limitation, samples of leaves, branches, stems, bark, and roots from Cypress plantations in Jintang, Jianyang, Yanting, and Jiange were collected by sampling method, and the moisture content, C, N, P and K contents, stoichiometry, and their correlations were tested and analyzed respectively. The results showed that: (1) The moisture content of each organ in Cypress plantations varied within the four counties (cities), with the highest levels in branches and the lowest in stems. Latitude, annual average temperature, and altitude were common factors influencing the moisture content of different parts of Cypress trees in diverse regions. (2) Two-factor analysis of variance showed that there were significant differences in the mass fractions of C, N, P, K and their stoichiometric ratios in Cypress plantations (P<0.05). (3) The C content in all organs of Cypress plantations in different regions was generally high, while the contents of N and P were generally low. The C mass fraction in the stems of Cypress trees in Yanting was significantly different from that in the other three regions (P<0.05), and the N mass fraction in the stems, bark, and leaves of Cypress trees in Jintang was significantly higher than that in the other three regions (P<0.05). There were no significant differences in the P mass fraction in the roots, bark, and leaves of Cypress trees among the regions (P>0.05). (4) The N/P values of roots, bark, and branches of Cypress trees in Jiange were significantly lower than those in the other three regions (P<0.05), and the N/P values of stems and leaves of Cypress trees in Jintang were significantly different from those in Jianyang and Jiange (P<0.05). Cypress plantations in Jiange were limited by N, while Cypress plantations in the other three regions were limited by P. (5) Latitude, mean annual temperature, elevation, and mean annual total precipitation within different regions all had a significant impact on the nitrogen content of cypress, but little influence on the C, P and K contents. (6) In the future forest management, Jiange should adopt selective cutting of cypress trees and replanting alder and other carbon-fixing broad-leaved tree species to form a mixed plantation of conifers and broad-leaved trees. The other 3 counties (cities) can reasonably increase the application of P fertilizer if conditions permit.