  The jet of the quasar 3C273 is observed at different spectral bands. This jet
has a knot structure. Jet radiation in radio and optical bands are connected
with synchrotron mechanism, while the emission mechanism producing the X-rays
is controversial. We suppose that the X-rays observed for two knots nearest to
the quasar can originate from the inverse Compton scattering of external source
radiation on relativistic electrons. But in the jet region with constant low
X-ray intensity the inverse Compton scattering on cosmic microwave background
photons (IC/CMB) is essential because the energy density of external source
decreases. Upon this scenario the constraints on the angle between the jet axis
and line sight values have been obtained. Also, some physical parameters for
two nearest knots of the jet of 3C273 have been estimated.
