The effects of catalyst,rate of feed and reaction time as well as other influence factors in the process of preparing dibromoneopentyl glycol(DBNPG) by brominating pentaerythritol with gaseous HBr in the presence of an inert solvent wore discussed,and give the proper conditions: Using a kind of monoacids between 2~10 carbonatoms as catalyst at the amount of 2. 1 %~3. 3% based upon pentaerythritol weight,therate of feed is about 3: 1--4: 1,the time for draining water off condensate about 1. 53. 0 h and the total reation time about 7--13 h. Thus,the yield of DBNPG is 80% uponpentaerythritol weight.