An outburst with rich pulsations has been observed at 9.375 GHz on July 30, 1990. After analysing these pulsations, some interesting results are obtained: (1) The flux level of the burst rises as repetition frequency of pulsations increases, following a linear relationship; (2) The modulation degree of pulsations is inversely propotional to the flux level; (3) There is a good linear relationship between the energy of individual pulse and flux level too. Asimplest interpretations are proposed.