BACKGROUND – With the urgent demand for minimally invasive approach, since we do not have cryo device in most Chinese hospital, here we introduce a minimally invasive approach to accomplish Maze IV ablation with radiofrequency device. 
METHODS – The cardiopulmonary bypass was routine established via peripheral vessels, a 6 cm incision was made in the 4^th intercostal space. An extended atriotomy was made to supply a good exposure. We dissected the space of transverse sinus and free all the visceral layer of pericardium. A flexible hinged radiofrequency device plus ablation pen was used to mimic the open maze IV lesion. The left atrium appendage was closed with endocardial running suture. The mitral valve was repaired by annuloplasty and artificial chordae technique.  
RESULTS – The rhythm was returned to sinus rhythm after heart auto-rebeat. The cross-clamp time was 151mins and CPB time was 182mins. The patient was extubated at POD2 and discharged at POD 7.  .
CONCLUSIONS – It is reasonable to do a full maze IV ablation via minimally invasive incision with radiofrequency device.