A R-parity breaking SUSY model characterized by an effective bilinear violation with only $\tau$-lepton number breaking in the superpotential is outlined. The CP-odd Higgs boson masses and those of charged Higgs bosons are discussed. In the model, several interesting mass mixings else such as the mixing between $\tau$ lepton and charginos etc in the model are discussed too. Being one of example, we have computed the mixing production $e^{+} e^{-} \to \tau^{\mp} \tilde{\kappa}^{\pm}_{i} (i=1,2)$ in e^+ e^- colliders, where $\tau^{\mp}, \tilde{\kappa}^{\pm}_{i}(i=1,2)$ denote the physical $\tau$ lepton and charginos.
Comment: 23 pages, include 6 figures, corrected some typos and added some references