The photosynthetic parameters were measured using a photosynthetic apparatus (Li-6400). The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) of the fully expanded leaves were measured and their variation laws will be calculated. The contents of chlorophyll a (Chl.A) and chlorophyll b (Chl.B) of the leaves from Dendrobium nobile were determined according to the method of Tehseen et al. (Asghar et al., 2016). After crushed, 0.1 g fresh leaves were extracted with 5 mL of 80% acetone in the dark for 24 h. The extracts were combined and made up to 25 mL. 80% acetone was used as a control, and the colorimetric was tested at spectrophotometers at 663 nm and 645 nm, and the chlorophyll content were calculated.