In　this　paper,　a　simple　method　for　ellipse　detection　is　proposed　and　applied　in　central　catadioptric　camera　calibration.　It　consists　of　two　phases.　Firstly　it　locates　ellipse　center　candidates　using　center　symmetry　of　ellipses,　and　the　detected　edge　points　are　grouped　into　several　subsets　according　to　the　center　candidates.　Then　all　the　ellipses　are　fitted　by　performing　RANSAC　for　each　subset.　We　also　present　an　approach　for　calibrating　a　central　catadioptric　camera　based　on　the　bounding　ellipse　of　the　catadioptric　image.　Using　the　proposed　ellipse　detection　method,　we　can　easily　detect　the　bounding　ellipse.　As　a　result,　a　simple　self-calibration　can　be　realized,　which　can　be　used　in　some　applications　where　high　accuracy　of　the　calibration　is　not　required.　Experiments　show　the　proposed　method　is　effective.