Fermi/LAT observations of Lobe-dominant Radio Galaxy 3C 207 and Possible Radiation Region of the Gamma-Rays

3C 207 is a lobe-dominant radio galaxywith one sided jet and the bright knots in kpc-Mpc scale were resolved in the radio, optical and X- raybands. It was confirmed as a gamma-rayemitter with Fermi/LAT, but it is uncertain whether the gamma-rayemission region is the core or knots due to the low spatial resolution of Fermi/LAT. We present an analysis of its Fermi/LAT data in the past 9 years. Different from the radio and optical emission from the core, it is found that the gamma-rayemission is steady without detection of flux variation over 2 sigma confidence level. This likely implies that the gamma-rayemission is from its knots. We collect the radio, optical, and X- raydata of knot-A, the closest knot from the core at 1 arcsec, and compile its spectral energy distribution( SED). Although the single-zone synchrotron+SSC+IC/CMB model by assuming knot-A at rest can reproduce the SEDin the radio-optical-X- rayband, the predicted gamma-rayflux is lower than the LAT observations and the derived magnetic field strength deviates the equipartition condition with 3 orders of magnitude. Assuming that knot-A is relativistically moving, its SEDfrom radio to gamma-raybands would be well represented with the single-zone synchrotron+SSC+IC/CMB model under the equipartition condition. These results likely suggest that the gamma-rayemission may be from knot-A via the IC/CMB process and the knot should have relativistical motion. The jet power derived from our model parameters is also roughly consistent with the kinetic power estimated with the radio data.