Abstract: Amount of formaldehyde vapor adsorbed by bamboo charcoal was determined by spectrophotometry and the relations among adsorption amount,time and temperature were studied.Furthermore,the mechanism of formaldehyde adsorption and desorption on bamboo charcoal was discussed and the measuring method of formaldehyde adsorption was established.From SEM pictures of bamboo charcoal,the influence of particle size on amount of formaldehyde adsorption was investigated.The results showed that,under the adsorption condition of 55℃ and 3 h,the adsorption (amount) of formaldehyde on bamboo charcoal was maximal,up to 68.5 mg/g.Bamboo charcoal particle size has some effects on amount of formaldehyde adsorption but not obvious,which is mainly caused by its microstructure.The adsorption is mainly physisorption,so the desorption happens quite easily.In the process of desorption,the relation (between) the residual of formaldehyde and time follows the equation y=109.19x-1.1084,at correlative coefficient r=0.979 4.