Abstract: The paper aims to investigate the effect of extraction conditions on acidic substances of Artemisia ordosica and optimal extraction method, the experiment, combining single factor experiment and orthogonal design of 3 factors at 3 levels, was conducted to study acidic substances contents in roots, stems, leaves and seeds of Artemisia ordosica with different conditions treatment. The results showed that the optimal conditions for extraction were 48 h, 1:5, and 40℃ for roots; 48 h, 1:40, and 40℃ for stems; 72 h, 1:50, 40℃ for leaves; 72 h, 1:5 and 40℃ for seeds. The sequence according to the effect of the extraction results were as follows: solid/liquid ratio, extraction temperature, extraction time for roots, extraction temperature, solid/liquid ratio, extraction time for stems and leaves, solid/liquid ratio, extraction time, extraction temperature for seeds. Contents of detected acidic substances were higher than that with the others’ treatment under optimal conditions for extraction. The main acidic substances of detected were different in the different parts of Artemisia ordosica and were effected by multiple factors, such as extraction time, extraction temperature, solid/liquid ratio and their decomposition speed, etc.