Recently,extensiveempiricalevidenceshowsthatthetimingofhumanbehaviorsobeys non-Possionstatisticswithheavy-tailedintereventtimedistribution.Inthispaper,weempiricallystudythecorrespondencepatternofagreatChinesescientist,namedHsue-ShenTsien.Boththeintereventtimedis