Novel naphthalocyanine derivatives are disclosed in the specification are useful for forming a recording layer in an optical recording medium. These derivatives are represented by the following formula (I): ##STR1## in which k, l, m and n, which may be the same or different, are zero or integers of 1 to 4, k+l+m+n being an integer of 1 or more; R.sup.1 's in a number of (k+l+m+n), which may be the same or different, are alkyl groups, substituted alkyl groups, or aryl groups; M is Si, Ge or Sn; and two Y's, which may be the same or different, are aryloxyl groups, alkoxyl groups, trialkylsiloxyl groups, triarylsiloxyl groups, trialkoxysiloxyl groups, triaryloxysiloxyl groups, trityloxyl groups, or acyloxyl groups. These derivatives are especially useful in the preparation of an optical recording medium.