Tent spaces were introduced by Coifman, Meyer and Stein in 1980’s. They are well adapted for the study of many subjects in the classical analysis. However, its definitionrelies on two geometric object of Euclidean spaces: ”cones” and ”cubs” which make it difficult to consider its generation in the case where geometric structure are missing. We define and study Tent spaces by using semigroup of operators. As an application, we prove a duality inequality for H1 − BMO spaces associated with general subordinated Poisson semigroups.