  We report the discovery of a giant planet in the KMT-2016-BLG-1397
microlensing event, which was found by The Korea Microlensing Telescope Network
(KMTNet) alone. The time scale of this event is t_E = 40.0 +- 0.5 days and the
mass ratio between the lens star and its companion is q = 0.016 +- 0.002. The
planetary perturbation in the light curve is a smooth bump, resulting in the
classical binary-lens/binary-source (2L1S/1L2S) degeneracy. We measure the V -
I color of the (putative) two sources in the 1L2S model, and then effectively
rule out the binary source solution. The finite-source effect is marginally
detected. Combined with the limits on the blend flux and the probability
distribution of the source size normalized by the Einstein radius rho, a
Bayesian analysis yields the lens mass M_L = 0.45+0.33-0.28 M_sun, at distance
of D_L = 6.60+1.10-1.30 kpc. Thus the companion is a super-Jupiter of a mass
m_p = 7.0+5.2-4.3 M_J , at a projected separation r = 5.1+1.5-1.7 AU,
indicating that the planet is well beyond the snow line of the host star.
