Strong shock waves in a bubbly liquid are examined by using a simple numerical model based on the K-dV-Burgers equation. In this model, two kinds of coefficients of the equation are switched with each other depending upon the relative magnitude of the peak amplitude to a certain threshold. Irregular behavior is numerically found both in the oscillatory wave trains behind the shock front and in the evolution of the shock front itself. Since such irregularity is enhanced when the nonlinearity increases, the wave behavior is considered to be chaotic. ©2000 American Institute of Physics.