We obtain the optimal time-decay rate of classical solutions to two-fluid Euler-Maxwell equations in ℝ ( = 2, 3), which is a remaining question in the framework of critical Besov space (see [1]). The system is of regularity-loss, so it is difficult to get decay rates in the solution space. In this paper, the new estimate of -type and something like "square formula of Duhamel principle" are mainly used. It is shown that in the critical Besov space, the solution decays to constant equilibrium at the rate (1 + )
K E Y W O R D S--estimates, regularity-loss, minimal decay regularity, two-fluid Euler-Maxwell equations