Based on the branching fractions of J/ψ(ψ(2S )) → VP from different collaborations, pseudoscalar mixing is extensively discussed with a well established phenomenological model. The mixing angle is determined to be 14 by fitting to the new world average if only quark content is considered. After taking into account the gluonic content in η' and η' simultaneously, the investigation shows that η favors only consisting of light quarks, while the gluonic content of η' is Z 2 η' = 0.30 ± 0.24.
