The powerful jet noise containing discrete frequencies had been studied for the supersonic jet issuing from asymmetric nozzle with the oblique outlet. The discrete frequency noise was discussed to clarify the noise characteristics and generation mechanism. The behavior of supersonic jet was visualized by the instantaneous shadowgraph method. The vibration of total pressure in supersonic jet was measured using the probe having the built-in pressure transducer. The frequency spectrum of total pressure was analyzed using FFT. As the result, it was found that the peak frequency of total pressure vibration was mostly in agreement with the first peak of discrete frequency noise.