Abstract: Aging behaviour of polycyclic aromatic hydrocarbons(PAHs) phenanthrene and anthracene in organo-mineral aggregates from black soil were studied under laboratory incubation.Changes in their extractability and aging rate in different fractions of organo-mineral aggregates were determined through extraction by dichloromethane.After incubation for 90 days,the extractability of phenanthrene and anthracene were seen to be decreased about 10% and 30%,respectively.In clay fractions,the aging rate in the first period(from 0 to 15 days) appeared highest,while in the other three fractions,the higher aging rates existed basically in the period from 15 to 28 days.