Abstract This study evaluated the distribution pattern of various life-form spectra along the Moghan-Sabalan rangelands, Ardabil province, Iran. Sampling was conducted in eleven elevation classes at 300 m elevation intervals (100-3300 meters above sea level, masl). In each elevation interval, 30 quadrats (1×1 m) were used to collect vegetation data (density, frequency and canopy cover). To detect significant differences along elevational gradient, an analysis of variance (ANOVA) and Duncan test were used to compare averages and grouping of the plant index. Regression analyses were employed to explore the inter-relationship of elevation with various life-form spectra. Overall, 386 species, which comprised 44 families and 200 genera, were identified in the study area. Therophytes and hemicryptophytes were the most frequent life form constituted each with respectively 164 and 162 species, while phanerophytes with 3 species were the least frequent form of life. Density, canopy cover, IVI, species richness and diversity of therophytes decreased with elevation, while hemicryptophytes species richness and evenness increased.