To investigate effects of warming on leaf morphology, anatomical structure, root activities and above-and below-ground parts of Kobresia pygmaea and Kobresia tibetica in alpine meadow and alpine swamp of the Tibetan Plateau in China, a warming experiment was carried out using open-top chambers to simulate climatic warming. The results showed that the warming significantly increased the leaf length and leaf number of the Kobresia pygmaea, and significantly increased the plant height and leaf length in Kobresia tibetica. But there were no significant effects of warming on the thickness of upper cuticle, low cuticle, the cuticular layer of the low cuticle cell, the length and the width of mesophyll cells in the Kobresia pygmaea and Kobresia tibetica. Warming significantly increased the root active absorption area in Kobresia pygmaea. Moreover, warming decreased the N concentrations of aboveground in Kobresia pygmaea, but no effect of warming on C and P concentration was detected, warming decreased the C and N concentrations of aboveground in Kobresia pygmaea, but have no effect of warming on P concentration. Increasing C/N ratio in aboveground with warming indicated that warmer temperature could increase nitrogen use efficiency in both Kobresia pygmaea and Kobresia tibetica. Warming didn't affect C, N, and P stoichiometry in the belowground part of Kobresia pygmaea, but decreased the C concentration and C/N ratio in below-ground of Kobresia tibetica.