  We report on the results of medium-resolution spectroscopy of GRS 1915+105 in
the near-infrared H and K band using the 8m VLT at ESO. We clearly identify
absorption bandheads from 12CO and 13CO. Together with other features this
results in a classification of the mass-donating star in this binary as a K-M
III star, clearly indicating that GRS 1915+105 belongs to the class of low-mass
X-ray binaries (LMXB).
