The evergreen oak (Quercus aquifolioides Rehder & E.H. Wilson) forests are widely distributed in the subalpine zone on the Hengduan Mountains,southwestern China. To understand plant responses to elevational gradient,we studied the leaf-form characteristics of vascular plants growing in 15 Q. aquifolioides community along an elevational gradient from 2200 to 3600 m.a.s.l. on the Balang Mountain,Wolong Nature Reserve, SW China. The majority of the plant species occurring in Q. aquifolioides populations belonged to the microphyll leaf size class (36.09% of the total plant species recorded). Plants with nanophyll-and mesophyll-sized leaf had a proportion of 25.64% and 25.22%,respectively. Plants with macrophyll-and megaphyll-sized leaves accounted for 6.82%-9.94% and 0.00-0.71%,respectively. Plants with macrophyll-sized leaves of the total plant species recorded in the populations across the elevational transect. Plants belonging to the leptophyll leaf size class had a proportion of 1.28%-5.59% only. The proportion of plants with microphyll-sized leaves decreased then increased and then decreased again with increasing elevation,with the lowest proportion at 3000 m a.s.l. Single-leaved plants had a proportion of 75.52% (ranging from 73% to 78%) with a minimum value of 57.23% at 2700 m a.s.l. Compound-leaved plants accounted for 24.48% ranging from 21% to 26% across the Q. aquifolioides populations investigated. Membranous plants were abundant with a proportion of 46.03%,followed by orthophyll (29.17%),sclerophyll (22.00%),and thick sclerophyll (2.79%). Proportions of plants with membranous and thick sclerophyll leaves decreased,but those with orthophyll and sclerophyll leaves increased with increasing elevation. Entire-leaved plants (50.50%) and unentire-leaved plants (49.50%) had the same proportion in Q. aquifolioides populations,but the former changed with increasing elevation following a positive binomial distribution,and the latter following a negative binomial distribution.