To understand the effect of forest fire on regeneration of bamboo (Cephalostachyum pergracile), we compared the number of bamboo culms and clump dynamics both in unburned area (UB) and fire-burned area (FB) from 2008 to 2011. in mixed deciduous forest at Mae Klong Watershed Research Station, Kanchanaburi, Thailand. In this studied area, the gregarious flowering occurred in 2001. The 20 plots of 1.5x1.5 m were established in each site. Forest fire occurred three times in FB during the study period. The results showed that the shoot production and the diameter of culms were higher in UB than FB though the study period. In addition, the survival rate of culms was higher in UB than FB. These results indicate the fire destroy the new shoot and depress the survival bamboo. We also investigated the production of bamboo in gap and understory in fire burned area to understand the effect of light intensity on bamboo production. We found that the height of culms, number of culms per clump and culms diameter were higher in gap. This result suggested that lights supported bamboo production. Thus, forest fire destroys aboveground culms but still stimulate bamboo to produce new shoot, even though the culms size of FB is smaller than that of UB at same age.