[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.