Du, DS (reprint author), Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China.
Di-gluon fusion mechanism might account for the large branching ratios of B-->Keta'. But because we know little about the effective eta'gg vertex, there are large uncertainties in perturbative QCD estimations. In this paper, we try several kinds of eta'gg form factors and compare the numerical results with the experiment. We find that, though we know little about eta'gg form factor, if di-gluon fusion mechanism is important in B-->Keta', die branching ratios of die decays B-->K*eta' would be around 10(-5) which can be tested by future experiments.