In this study on the nature of pressure signals generated by a determi nistic or stochastic process in a bubbling fluidized bed, pressure fluctuation m easurements were carried out in a 300-mm-diamet column at 0.090 m and 0.40 m above the distributor for different gas velocities. The method of detecting determinis tic dynamic underlying pressure signals is proposed on the basis of predictabili ty of pressure fluctuations. The deterministic nature of dynamics in fluidizing system was verified. The deterministic level of dynamics in fluidizing system wa s analyzed for different locations of pressure measurements and different gas ve locities.