The responses of net photosynthetic rate (Pn) to light intensity and the CO2 concentration in leaves of homologous wild and cultivar Artemisia annua were studied. The maximum net photosynthetic rate (Pmax) was 18.78 μmol m-2s-1 for the wild-type and 22.38 μmol m-2s-1 for the cultivar. The light saturation point (LSP) was 1 183 μmol m-2s-1for the wild-type and 1 564 μmol m-2s-1 for the cultivar. The light compensation point (LCP) was 17 μmol m--2s-1for the wild-type and 18 μmol m-2s-1 for the cultivar. The apparent quantum yield (AQY) was 0.08μmol m-2s-1 for the wild-type and 0.075 μmol m-2s-1 for the cultivar. Those data indicated that A. annua could utilize high light irradiance and perfectly acclimate to low light condition. Pmax, LSP and maximum carboxylation rate of Rubisco (Vcmax) were significantly higher in cultivar A. annua than in the wild-type. LCP, AQY, maximum rate of electron transport (Jmax), rate of non-photorespiratory CO2 evolution in the light (Rd) and CO2 compensation point in absence of respiration in the light (Г*) were not significant difference between the wild-type and cultivar. High light irradiance enhanced A annua in photosynthetic capacity by increasing Vcmax and Jmax and therefore A annua should be cultivated in an open and sun-filled habitat.