[Objective] The population structure and distribution pattern of Aminopiptanthus mongolicus in different slope aspects of Beiza Mountain were demonstrated and the relations between A.mongolicus population and the surroundings were analyized.[Methods] Population structure and distribution pattern of A.mongolicus population in different slope aspects of Beiza Mountain were studied by using mean crowding, clumping index I, patchiness index, Cassie index, dispersal index(C) and parameter of negative binominal(K).[Results] (1) The highest population density of A.mongolicus was at sunny slope, which was 2.5 times of the half-sunny slope; and the population grew best at half-shaded slope. (2) The age structure at sunny slope, half-sunny slope and ridge were stable, the half-shaded slope was increasing; (3) The dispersal index at sunny slope, half-sunny slope and half-shaded was clump distribution, and the ridge was uniform distribution; (4) The pattern scales were as follows:sunny slope, 4 m×8 m; half-sunny slope, 4 m×4 m; half-shadedslope, 8 m×8 m; ridge, 4 m×8 m.[Conclusion] The growth status was well, the age structure was stable, and the most distribution patterns were clump distribution, the pattern scale was different in imparity distribution.