The?hourly?precipitation?data?of?11?meteorological?stations?during?1981-?-2015?in?Shanghai?were?used?to?study?the?varia-tion?characteristica?of?daily?precipitation?in?flood?season?(June-?September),?the?main?conclusions?are?as?fllows:?(1)?The?Shanghaiarea?daily?precipitation?frequency?shows?obvious?characteristics?of?the?double?peak?type?with?highest?probability?of?precipitationduring?17:00-?19:00?BST;?precipitation?intensity?showing?characteristics?of?single?peak?diurmal?variation?type?with?the?maximum?in-tensity?during?15:00-16:00?BST.?(2)?In?Shanghai,?local?scale?rainfall?events?occurred?most?frequently?in?August,?with?strongerhourly?rainfall?intensity?than?other?months;?In?June,?the?proportion?of?whole-?-region?scale?rainfall?events?is?obviously?more?than?oth-er?months,?the?hourly?rainfall?probability?was?significantly?higher?than?other?months?as?well.?(3)?From?moming?to?noon,?the?regionalscale?and?whole-?-region?scale?rainfall?event?shows?increasing?trend?in?recent?30?years,?resulting?in?increasing?precipitation?frequencyand?no?change?on?rainfall?intensity;?from?aftemoon?to?evening,?the?local?scale?rainfall?events?shows?increasing?trend,?resulting?inenhanced?rainfall?intensity?at?most?observation?sites.