Abstract: Using the gas adsorption method,the specific surface area of standard alumina powders was determined on ASAP2020 specific surface area and porosity analyzer made in Micromeritics Instrument Corporation of USA.And influencing factors on the specific surface area test results were studied.The results show that the adsorption system dead volume,sample amount and degas conditions all had obvious effects on the testing results,and the ideal testing condition for alumina powders with low specific surface area was that 2.5-3 g sample was desorbed at 250 ℃ for 2 h.This study could provide a reference for the low specific surface area determination.