Abstract: The structure of low pressure condition plasma sprayed TiO₂ coatings was investigated. The structure of TiO₂ coatings was affected by the degree of oxygen loss during plasma spraying. The oxygen loss is influenced to a great extent by the quantity of H2 in plasma gas and to a certain extent by the atmospheric pressure, but almost not by the output of plasma and spraying distance. Ti₃O₅ in the coating was increased with the increase of atmospheric pressure from 100×133.322Pa to 400×133.322 under constant H2 gas quantity.