Extracting justifications for web ontology language (OWL) ontologies is an important mission in ontology engineering.In this paper,we focus on black-box techniques which are based on ontology reasoners.Through creating a recursive expansion procedure,all elements which are called critical axioms in the justification are explored one by one.In this detection procedure,an axiom selection function is used to avoid testing irrelevant axioms.In addition,an incremental reasoning procedure has been proposed in order to substitute series of standard reasoning tests w.r.t.satisfiability.It is implemented by employing a pseudo model to detect “obvious” satisfiability directly.The experimental results show that our proposed strategy for extracting justifications for OWL ontologies by adopting incremental expansion is superior to traditional Black-box methods in terms of efficiency and performance.