In this paper, we study ICE-closed (= Image-Cokernel-Extension-closed) subcategories of an abelian length category using torsion classes. To each interval [U , T ] in the lattice of torsion classes, we associate a subcategory T ∩ U ⊥ called the heart. We show that every ICE-closed subcategory can be realized as a heart of some interval of torsion classes, and give a lattice-theoretic characterization of intervals whose hearts are ICE-closed. In particular, we prove that ICE-closed subcategories are precisely torsion classes in some wide subcategories. For an artin algebra, we introduce the notion of wide τ -tilting modules as a generalization of support τ -tilting modules. Then we establish a bijection between wide τ -tilting modules and ICE-closed subcategories satisfying certain finiteness conditions, which extends Adachi-Iyama-Reiten's bijection on torsion classes. Furthermore, we discuss the Hasse quiver of the poset of ICE-closed subcategories for the hereditary case by introducing a mutation of rigid modules.Contents 24 6.1. Some properties on the lattice of ICE-closed subcategories 24 6.2. Examples of computations on ICE-closed subcategories 26 References 29