Leaf economic spectrum (LES) predicts more carbon (C) investment in the construction of high-density tissues in arid environments, a slow-growing and conservative strategy. Succulent plants have evolved an unique strategy to adapt to drought. However, we are unclear whether and how leaf trait syndromes of succulent plants are involved in LES. Here, we compared a series of leaf traits of 12 succulent plants and 27 non-succulent plants of desert grassland ecosystems in the Hexi Corridor, northwest of China. We observed that leaf trait syndromes markedly differed between succulent plants and non-succulent plants. Specifically, compared with non-succulent plants, succulent plants had low leaf dry matter contents (LDMC), high sponge mesophyll fraction, low palisade mesophyll fraction, and low vein density and fraction. In contrast, no significant differences in dry mass per leaf area (LMA), leaf nitrogen concentration (LNC) and leaf phosphorous concentration (LPC) between succulent plants and non-succulent plants were detected. Moreover, we observed that LDMC of succulent plants was negatively correlated with sponge mesophyll fraction and positively with palisade mesophyll fraction, while LDMC of non-succulent plants was positively correlated with vein fraction per leaf volume.These findings indicate that, analogous to non-succulent plants that invest more C to construct high-density tissue to tolerate drought, succulent plants invest more C to construct low-density tissue, a specialized water-storing mesophyll, to alleviate the dependence on soil water supply. Therefore, these results highlight that specialized water-storing tissues should be recognized as important conservative traits of succulent plants, but leading to deviations from LES-prediction. These findings would extend our knowledge on the application of LES to some specialized plants adapted to the stressed environments.