Prediction on CP Violation in Long Baseline Neutrino Oscillation Experiments

We have predicted CP violation in the long baseline accelerator experiments taking into consi deration the recent LSND data and the atmospheric neutrino data. By using both data, we can get unambiguous results for CP violation. Those data prefer the mass hierarchy $m_3\simeq m_2 \gg m_1$ with $m_3=O(1 eV)$ and the flavor mixings $|U_{e 1}| \simeq 1$ and $|U_{\mu 1}| \ll 1$. The estimated upper bound of CP violation is 0.006, which may be observable in the long baseline accelerator experiments. The matter effect, which is not CP invariant, is found to be very small.