Hadronic decays of charmonia from BESII

Recent results on charmonia decays at BESII/BEPC are reported, including the observation of psi'-->K_S K_L, psi'--> Vector + Tensor and psi'--> Vector + Pseudoscalar for the measurement of the relative phase between the strong and electromagnetic decays of psi' and a test of the pQCD ``12% rule'' between psi' and J/psi decays; the test of the color-octet mechanism via chi_cJ --> p \bar{p} and chi_cJ-->\Lambda \bar{\Lambda}; the first observation of chi_c0--> f_0(980)f_0(980); and a study of the psi' and chi_cJ decays with K_S K_S in the final states.