Leaves and fine roots play a crucial role as vegetative organs in both the aboveground and underground parts of plants. The stoichiometric characteristics of carbon (C), nitrogen (N), and phosphorus (P) in these organs reflect the strategies of nutrient adaptation and the balance of elements. In this study, we examined the C, N, and P content as well as the C : N, C : P, and N : P ratios in leaves and fine roots of 21 desert plants in arid region of Northwest China. The plant species were categorized into three life forms: shrubs, forbs, and grasses. We investigated the correlation and differences in C, N, and P contents and their ratios between leaves and fine roots, as well as among the three life forms. Our findings revealed the following: 1) The C content of leaves and fine roots in desert plants of the northwest arid region remained relatively stable, while the N and P contents of leaves were higher compared to fine roots. This suggests that in arid habitats, plants allocate nutrients to their aboveground parts to carry out essential life activities. Moreover, there was no significant difference in N : P between leaves and fine roots, indicating a consistent nutrient absorption strategy and distribution pattern between the above-ground and underground parts of plants. 2) The significant differences were observed in the content of C, N, and P, as well as in the ratios of C : N and C : P, among the leaves and fine roots of various life forms. Shrubs and grasses exhibited higher C : N and C : P ratios, suggesting their inclination towards conservative nutrient adaptation strategies. On the other hand, forbs displayed higher N and P content, indicating their preference for fast-growing resource competition strategies. 3) The study revealed a noteworthy positive correlation between the N and P contents in both leaves and fine roots of 21 desert plants. This finding suggests the presence of an interaction between N and P elements in desert plants within the arid region of Northwest China. 4) The C, N, P contents and C : N, C : P ratios between leaves and fine roots exhibited an isometric growth relationship. This suggests that the allocation of plant photosynthetic products and nutrients between aboveground and underground parts is proportionate. However, it is important to note that this relationship is influenced by the life forms of the plants. The results above indicate that plants in arid region of Northwest China have different nutrient adaptation strategies depending on their life forms. These strategies have a synergistic effect between leaves and fine roots, providing an experimental basis for further understanding the nutrient utilization strategies of desert plants in this region.