Th is wo rk is devo ted to a dynam ical modeling m ethod of resou rce allocat ion fo r info rm at ion system s based on co lou red Pet ri net s. The m ethod can be u sed in the mo re comp lex en terp rise info rm at ion system s. The def in it ion s of system h ierarchy model and execu t ion graph are p ropo sed. System developers can pay mo re at ten t ion on differen t level of the model acco rding to their concern. A nd the t ran sfo rm at ion m ethod betw een execu t ion graph and pet ri net are analyzed. Based on the p ropo sed dynam ical h ierarchy model, system developers can evaluate the system dynam ical perfo rm ance and adju st the resou rce allocat ion of info rm at ion system s to m eet the perfo rm ance requ irem en t. The modeling p rocess of info rm at ion system s is given in detail. A nd app licat ion examp le is p resen ted.