  In CP violation measurements in asymmetric B-factory experiments, a
determination of the B flavor of the neutral B mesons is necessary. A new
method to this purpose using only three vectors of charged particles has been
developed. This method (weighted charge method) does not require either lepton
identification or charged-kaon identification. The tagging efficiency,
probability for incorrect tagging, and effective tagging efficiency of this
method are 43.1, 18.3, and 17.3\%, respectively.
