Experimental Study on the effect of fine-granular fluidized bed's furnace surface roughness on (quasi) dispersion fluldhatinn properties was included in thiS paper.The particlesof diameter from 0.076 to 0.45 mm were used in the test.With different kinds of furnace linersand a resistant measuring device made by ourselves,the relations among surface roughness,the distribution and the thickness of fluidizating dead zone near the surface were got.Considering measuring results of coefficients of friction between fine particles and different kinds of furnaces,a theoretical analysis on the relation was made.The researching results showed that a rough surface might result in thicker fluidizd atate deadzone and lead to fluidization change from aggregative fluidizationinto dispersion fluidization more quickly.