Experimental study was carried out on heat transfer of horizontal finned tube bundles in the freeboard region of fluidized bed, which was with an internal square cross section of 400x400mm and a height of 1020mm. Each finned tube arranging in staggered 2 rows was with a spiral welded fin, which was a height of 19.4mm, a thick of 2mm and a pitch of 9mm, around a φ34 steel tube. It was found that average heat transfer coefficient of finned tube was smaller than that of bared one because those finned tubes prevent from being activity and being expansion of the particles in bed. And ratio of heat transfer on finned tubes to bared was converged into 0.6 when those tubes completely immersed in bed. Furthermore it was clarified that it needs more fine particle, lower height of tubes and some proper height of static bed as proper conditions were needed.