  The FNAL experiment E773 has measured the phases Phi_{+-} = (43.35 +- 0.70 +-
0.79) degree and Phi_{00}-Phi_{+-} = (0.67 +- 0.85 +- 1.1) degree of the CP
violating parameters eta_{+-} and eta_{00} in the decay of neutral kaons into
two charged or neutral pions. These preliminary results test CPT symmetry and
show no evidence for a violation. In addition we present a preliminary
measurement of Delta m = m_L - m_S = (0.5286 +- 0.0029 +- 0.0022)*E+10 hbar/sec
and tau_S = (0.8929 +- 0.0014 +- 0.0014)*E-10 sec. The first errors are
statistical and the second errors are systematic for above results.
