We present K band photometry of the region including the radio error box of
the soft X-ray transient 4U1630-47 during its 1998 outburst. We detect a v
ariable source at K = 16.1 mag located inside the radio error circle which
we identify as the counterpart to the X-ray source. We discuss the properti
es of the source, and conclude that it is most likely a black-hole X-ray bi
nary similar to 4U1543-47, GROJ1655-40 or SAXJ1819.3-2525, containing a rel
atively early-type secondary.