The ordinary fluorescence of Er3+in Y2O3and LaF3crystals is observed when the crystals are excited with 6328‐Å, He‐Ne laser radiation. From the linear power dependence of the 6800‐Å fluorescence and the quadratic power dependence of the 5640‐ and 3900‐Å fluorescence on the 6328‐Å excitation, a single‐photon excitation for the 6800‐Å fluorescence and a double‐photon stepwise excitation for the 5640‐ and 3900‐Å fluorescence were proposed. The calculated photon flux of the 5640‐Å fluorescence based on the two‐photon stepwise excitation agrees with the estimated observed value.