In this article, we calculate the nonfactorizable soft contributions in the B-->eta(c)K,chi(c0)K decays with the light-cone QCD sum rules approach. Our results show that the nonfactorizable corrections from the soft-gluon exchanges in the decay B-->eta(c)K are of (15-30)% and should be taken into account. As for the decay B-->chi(c0)K, the factorizable contributions are zero and the nonfactorizable contributions from the soft hadronic matrix elements are too small to accommodate the experimental data.