Preliminary results of a new measurement of the differential electron excitation cross section of the O I (3P→1D) transition near threshold confirm the presence of a large peak in the inelastic cross section at 5 to 6 eV. The new results are compared with previous measurements and theoretical calculations. The near-threshold shape of the O I (3P→1D) cross section has interesting implications for the aeronomy of the thermosphere. ¿ American Geophysical Union 1992