Abstract:The past few decades have seen a resurgence of interest in biological allometry. Specifically, a number of recent studies has suggested a –4/3 invariant scaling relationship between mass and density that is universally valid for tree-dominated communities, regardless of their phyletic affiliation or habitat. In the present study, we test this scaling relationship using a comprehensive forest biomass database, including 1 266 plots of six biomes and 17 forest types across China. The present study shows that the scaling exponent of the mass-density relationship varies across different tree-dominated communities and habitats. This great variability in the scaling exponent makes any generalization unwarranted. Although inappropriate regression methods can lead to flawed estimation of the scaling exponent, inconsistency of theoretical framework and empirical patterns may have undermined the validity of previous work.(Author for correspondence.Tel: +86 10 6488 8996; Fax: +86 10 6485 9781; E-mail: haitaoli@public.bta.net.cn)