  We present results of optical identification of the ASCA Large Sky Survey.
X-ray sources which have hard X-ray spectra were identified with type-2 AGN at
redshifts smaller than 0.5. It is supported that the absorbed X-ray spectrum of
type-2 AGN makes the Cosmic X-ray Background harder in the hard X-ray band than
type-1 AGN, which is main contributer in the soft X-ray band. Absence of type-2
AGN at redshift larger than 1 in the identified sample, which contrasts to the
existence of 6 broad-line QSOs, suggests a deficiency of so-called ``type-2
QSO'' at high redshift.
