The present invention provides a method for recording and reproducing with an optical recording medium, with which either in-groove recording or on-groove recording is selected according to the type of recording medium, and information can be recorded and reproduced with good signal quality. To this end, a laser beam reflected by an information recording layer is received by a photodetector that has been split into at least two parts by a split line parallel to the direction of the grooves, in a region in which the groove width is greater than the width between grooves, and it is determined whether the grooves on the side where the laser beam is incident are convex or concave on the basis of a sum signal and difference signal of the photodetection signals outputted from the split photodetector.