This dataset includes measurements of various plant physiological traits in alpine meadow plants from the Tibetan Plateau under nitrogen gradients and herbivory treatments, aiming to provide data support for studying plant photosynthesis and physiological responses under different nitrogen levels and insect herbivory pressures. The data records key plant traits from the aboveground parts of two plant species in the alpine meadow, including photosynthesis rate (Pn, µmol·m⁻²·s⁻¹), stomatal conductance (Gs, mol·m⁻²·s⁻¹), chlorophyll relative content (Chl, SPAD), leaf nitrogen content (N, mg·g⁻¹), tannin content (CT, mg·g⁻¹), total phenol content (TP, mg·g⁻¹), total alkaloid content (TA, mg·g⁻¹), leaf mass per unit area (LMA, g·m⁻²), and insect feeding intensity (%). Additionally, the dataset includes environmental variables such as nitrogen addition gradients and herbivory treatment types. All data are presented in tabular format, with metadata including plant species, nitrogen addition concentrations, and herbivory treatments. This dataset is suitable for research in plant physiology, ecology, and climate change, particularly supporting meta-analyses and studies on adaptive strategies that investigate how plants respond to multiple environmental stresses such as nitrogen gradients and insect herbivory. There are no legal or ethical restrictions; users are encouraged to cite relevant research articles when using the data.