We explore the use of galaxy bispectra with multitracer technique as apossible probe of primordial non-Gaussianities. We forecast future constraintson non-linearity parameters, $f_{\rm NL}^{\rm eq}$ and $f_{\rm NL}^{\rm orth}$,which respectively characterize the equilateral- and orthogonal-typesprimordial bispectra, and show that the multitracer analysis would be effectivewith reducing the cosmic-variance noise if the number density of galaxies ishigh enough. We find that the measurement of galaxy bispectrum by future galaxysurveys can reach the constraints on the non-local type primordialnon-Gaussianities to the level severer than current one which has been obtainedby cosmic microwave background observations.
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