The subject of the present invention targets at providing, despite a condition that the length of record tag and the length of a blank area between the two neighboring record tags are less than the analysis margin, an optical recording disc recording and reproducing the data constituted by a record tag row containing these record tags and the blank area and significantly increasing the recording capacity in an expected manner. The solution of the present invention relates to an optical recording disc, which is carried out by using a laser beam L to record and reproduce data and is characterized by: including a decomposition reaction layer 5 containing a platinum oxide as its composition and a light-absorbing layer 7; including a laminate formed by sandwiching a second dielectric layer 6; forming holes and discharging micro-particles of platinum from the hole so as to form the record tag on the decomposition reaction layer 5; and having a particle diameter ranging from 2nm to 15nm for the micro-particle of platinum.