The photospheric abundances for the cool component of the symbiotic star CH Cyg were calculated for the first time using high-resolution near-infrared spectra and the method of of standard LTE analysis and atmospheric models .
The iron abundance for CH Cyg was found to be solar , [ Fe/H ] = 0.0 \pm 0.19 .
The atmospheric parameters ( T _ { eff } = 3100 K , \log g = 0.0 ( cgs ) , \xi _ { t } = 2.2 km s ^ { -1 } ) and metallicity for CH Cyg are found to be approximately equal to those for nearby field M7 giants .
The calculated [ C/H ] = -0.15 , [ N/H ] = +0.16 , [ O/H ] = -0.07 , and the isotopic ratios of ^ { 12 } C/ ^ { 13 } C and ^ { 16 } O/ ^ { 17 } O are close to the mean values for single M giants that have experienced the first dredge-up .
A reasonable explanation for the absence of barium star-like chemical peculiarities seems to be the high metallicity of CH Cyg .
The emission line technique was explored for estimating CNO ratios in the wind of the giant .