Abstract: The North China larch was used as the raw material to extract larch arabinogalactan by flash- extraction,based on single factor experiments,extraction condition was optimized by the response surface analysis. The results showed that the optimal conditions of extraction of the larch arabinogalactan from the North China larch were as follows: extraction temperature 70 ℃,flash- extraction time 1.6 min,solid- to- liquid( g / m L) ratio 1 ∶ 16 and extraction time 22 min.Under this condition,the maximal content of larch arabinogalactan was up to 14.30% ± 0.05%.By using scanning electron microscopy( SEM) analysis of the arabinogalactan samples,it was found that its distribution was the irregular geometry. And the infrared spectrum( IR) analysis showed that it contained a typical groups of saccharide compounds,also its trend was almost consistent with the standards.