The long GRB 100728A (Swift/BAT trigger 430151: Canizzo et.al, GCN 11004) triggered Konus-Wind at T0=8300.008s UT (02:18:20.008) The burst light curve shows a complex structure with a total duration of ~200 s. There is a hint of a weaker emission lasting at least to T0+290 s. The emission is seen up to several MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB100728_T08300/ As observed by Konus-Wind the burst had a fluence of 1.95(+/-0.35)x10-4 erg/cm2, and a 256-ms peak flux, measured from T0+27.392s, of 4.2(+/-0.7)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+137.216 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model, for which: the low-energy photon index alpha = -0.65 (-0.09, +0.09), the high energy photon index beta = -2.5 (-0.3, +0.2), the peak energy Ep = 305(-25, +27)keV (chi2 = 88/84 dof). The spectrum at the maximum count rate (measured from T0+24.832 to T0+31.488 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model, for which: the low-energy photon index alpha = -0.47 (+/-0.15), the high energy photon index beta = -2.6 (-0.3, +0.2), the peak energy Ep = 390(-48, +63)keV (chi2 = 84/84 dof). All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.