Abstract: Paeonia ludlowii is a unique, rare and endangered plant species in Tibet with narrow distribution less than 10 km² in area. Totally there were about 6 000~7 000 plants of the species in the area. The individual spatial distribution pattern was studied by applying aggregation density index and dot distribution pattern analysis of 3×17 primary matrixes of its population characteristics based on field investigation into 17 plots in 3 zones with natural distribution of Paeonia ludlowii. The results indicated that Paeonia ludlowii belonged to cluster distribution type, whose individuals could grow only at the forest edge and inside the forest gaps. It was deduced from the investigation that the distribution of Paeonia ludlowii at the forest edge and in the forest gaps in the river valleys was caused by the biological characteristics of the species and the environmental conditions.