Experimental investigations of the explosive behavior of pure oxygen bubbles in cyclohexane have been performed. For the investigations an autoclave containing a bubble generator was used and optical and pressure measurements were carried out. A shock wave was used to ignite the bubbles. The present work is the first where the explosion behavior of the bubble was investigated not only in the first oscillations after the incident shock wave passage, but for many oscillations after it. From these investigations two bubble ignition types are registered. One type of explosion is the well-known bubble explosion occurring in the first bubble oscillation after the shock wave impact. The other type was unknown up to now. It takes place after many bubble oscillations and has a significantly longer delay time before ignition. (C) 2003 Elsevier B.V. All rights reserved.