A bubbling fuel liquid (kerosene) jet is ejected normal to a high-temperature, high-speed airstream in order to control the spray shape and temperature profile when the liquid fuel flow rate is decreased to Jess than the standard flow rate (without bubbling air) under a certain constant ejecting pressure. The spray shapes are obtained by means of scattered-light photographs, and the combustion gas temperature of the airstream is measured at the exit of the combustor. In a room-temperature airstream, the position (height from the injector) of the maximum mass flow rate per unit area of dispersed liquid hardly changes and the maximum mass flow rate per unit area of dispersed liquid decreases, irrespective of the different flow patterns of the bubbling liquid jet, which forms a non-bubble type flow, a bubbly-type flow or a slug-type flow. In a high-temperature airstream, the sprays have similar shapes of the spray outer lines in spite of the different flow patterns of the liquid jet. These have the same tendency as the sprays in a roomtemperature airstream. However, there exists a discrepancy among the gas temperature profiles corresponding to the flow patterns of the liquid jet. When the liquid jet behaves as a bubbly-type flow and contains numerous small bubbles under the ejecting condition of a low injection air/fuel mass ratio, the gas temperature profiles are nearly the same as the spray of non-bubbling air, and the gas temperature decreases by the decreasing liquid fuel flow rate. Under the ejecting condition of a slug-type flow, which is an ejecting condition of a high air/fuel mass ratio with the cyclical injection of a liquid slug and an air slug containing a large bubble, the gas temperature at the relatively higher region of the spray is higher than at the lower region.