Research strategy in studying gas-solid fluidization at the Institute of Chemical Metallurgy (ICM) is outlined. Particle-fluid compromise is recognized to be the origin of the multi-scale dissipative structure in the system, to which multiple resolution is applied, leading to the establishment of the variational criterion for stability and the critical condition for choking. The dynamic behavior of such a heterogeneous structure in fluidized systems is formulated by carrying out wavelet analysis and resolving the whole process with respect first to scale, and then, to time and amplitude. Average approaches, as commonly used, are considered to be inadequate to describe transport behaviors in gas-solid fluidization. Discrete computer simulation on micro-scale is regarded to be a promising approach to further understanding of the complicated mechanism of particle-fluid interaction.