  In this talk, we investigate Lepton Flavor Violating (LFV) tau decay by
R-Parity Violating (RPV) operators controlled by a non-Abelian discrete $Q_6$
family symmetry. We assume that only a family symmetry determines the whole
flavor structure of a model, and the model indicates specific predictions of
LFV tau decay processes by RPV operators. We predict $BR(\tau \to 3e)/BR(\tau
\to 3 \mu) \sim 4 m_{\mu}^2/m_{\tau}^2$ in a $Q_6$ family symmetric model.
