That sex pheromone was extracted by adult female of Psocids Liposcelis entomophila was first ensured by difference times spent by male to crawl to female and male. It is the first time in all the worlds that methods of extraction and bioassay test sex pheromone of tiny individual insect especially Liposcelis entomophila were studied. Average time spent by male to crawl to female and male were 20.00±2.44min and 70.50±6.56 min respectively in bioassay by self-made disc trap and there were significantly difference(p<0.01). This result indicated that it is female but not male that released sex pheromone. Two methods were used to extract female sex pheromone, including organic solvent dipping（n-hexene and dichloromethane）and dynamic headspace collecting and extracted by n-hexene and dichloromethane method. Three bioassay methods (self-made disc trap, mimicked storehouse and “Y" olfactometer) were used to examine the bioactivity of different crude extraction of sex pheromone. Using the disc trap designed by ourselves, extraction by n-hexene through dynamic headspace collecting method had the highest bioactivity, the trap coefficient and the trap number were 46.3%±4.2% and 14.6±1.0 respectively and were equivalent to the virgin of L. entomophila female, both difference was not significantly(p>0.05) but was significantly difference with other crude extraction (p<0.05). This result indicated that dynamic headspace collecting method could be used to collect sex pheromone of tiny individual L. entomophila adult female. The results of different bioassay showed that trap coefficient and the trap number of extraction by n-hexene in headspace collecting by “Y" olfactometer were highest 55.3%±6.3％ and 15.0±1.8, but these were not significantly different with trap coefficient and number in disc trap (p>0.05) and were significantly with trap coefficient and number in mimicked storehouse (p<0.05). In fact, disc trap could be used to trap L. entomophila.