We study the CP asymmetry of B-+/--> omega K-+/- with the inclusion of the rho - omega mixing mechanism. It is shown that the CP asymmetry of B-+/--> omega K-+/- experimentally measured (ACPexp) and conventionally defined (ACPcon) are in fact different, which relation can be illustrated as ACPexp=ACPcon+Delta ACP rho omega, with Delta ACP rho omega the rho - omega mixing contribution to ACPexp. The numerical value of Delta ACP rho omega is extracted from the experimental data of B-+/--> pi (+)pi K--(+/-) and is found to be comparable with ACPexp, hence, non-negligible. The conventionally defin...
