The present invention provides CD-RW which makes high velocity recording
at a level of at least 24-times velocity possible, rewritable DVD which
makes high velocity recording at a level of at least 6-times velocity
possible, and a recording method therefor, while maintaining
interchangeability with conventional CD-RW standards and rewritable DVD
standards.A rewritable optical recording medium comprising a substrate
and a phase-change type recording layer, wherein a portion in a
crystalline state corresponds to an unrecorded or erased state, and a
portion in an amorphous state correspond to a recorded state, to record
EFM modulated information by forming amorphous marks by irradiating the
recording layer with a recording laser beam, and wherein recording is
carried out by irradiating a recording laser beam having a wavelength of
about 780 nm through an optical system having a numerical aperture NA of
0.5 or 0.55, at 24-times velocity or 32-times velocity of the reference
velocity, where the reference velocity (1-time velocity) is a linear
velocity of from 1.2 m/s to 1.4 m/s, modulation m.sub.11 of record
signals is from 60% to 80%, the top value R.sub.top of the reflectivity
of the high pattern is from 15% to 25%, and jitters are at most 35 nsec.