An optical recording method for recording mark length-modulated information on a recording medium by using a plurality of recording mark lengths. The optical recording method comprises the steps of:

• when a time length of one recording mark is denoted nT (T is a reference clock period equal to or less than 25 ns, and n is a natural number equal to or more than 2),
• (i) dividing the time length of the recording mark nT into

  ₁T, ₁T, ₁T, ₂T, ₂T, . . . , ₁T, ₁T, _mT, _mT, ₂T

  in that order (m is a pulse division number; _i(_i+_i)+₁+₂=n; _i (1im) is a real number0; _i (1im-1) is a real number0; _m is a real number0; and ₁ is a real number of -2₁2 and ₂ is a real number of -2₂2);

• radiating recording light with a recording power Pw_i in a time duration of _iT (1im), and radiating recording light with a bias power Pb_i in a time duration of _iT (1im), the bias power being Pb_iPw_i and Pb_iPw_i+1; and
• (ii) changing m, _i, _i, ₁, ₂, Pw_i and Pb_i according to n of the time length nT of the recording mark;

  wherein the pulse division number m is 2 or more for the time duration of at least one recording mark and meets n/m1.25 for the time length of all the recording marks.