An ASCA observation of Cygnus X-3 on 1993 June 11, in its X-ray high i
ntensity state, has for the first time resolved the broad iron K line
emission into three components: a He-like line at 6.67 +/- 0.01 keV, a
H-like line at.6.96 +/- 0.02 keV, and a neutral line at 6.37 +/- 0.03
keV. The line intensities of the 6.67 keV and 6.96 keV lines are modu
lated with the 4.8 hr orbital period and are maximum when the continuu
m intensity is minimum. There is a sharp minimum of the line intensity
on the rising phase of the continuum intensity. An iron absorption ed
ge is observed at 7.19 +/- 0.02 keV. The optical depth of the absorpti
on edge varies from 0.3 to 0.5 and is in anti-phase with the overall X
-ray continuum modulation. The observed complexity of the iron K line
region is greater than that had been assumed in previous spectral mode
lling based on observations with lower resolution detectors.