  We report the discovery of low frequency quasi-periodic oscillations centered
at 0.11 Hz in the newly discovered 221 s X-ray pulsar XTE J1858+034. Among
about 30 known transient X-ray pulsars this is the sixth source in which QPOs
have been observed. If the QPOs are produced because of inhomogeneities in the
accretion disk at the magnetospheric boundary, the low frequency of the QPOs
indicate a large magnetosphere for this pulsar. Both the Keplerian frequency
model and the beat frequency model are applicable for production of QPOs in
this source. The QPOs and regular pulsations are found to be stronger at higher
energy which favours the beat frequency model. The magnetic field of the pulsar
is calculated as a function of its distance. The energy spectrum is found to be
very hard, consisting of two components, a cut-off power law and an iron
fluorescence line.
