According to a report by the local "Dogan" news agency on Tuesday, Turkish soldiers noticed a group of people who wanted to cross the border illegally and opened fire.
Several bullets hit the Syrian girl.
She was taken to a nearby hospital in southern Turkey where she died.
The Turkish army reassured that the military made several warning shots.
The little Syrian girl was shot dead for trying to pass the border as Turkey has long been criticized by Syrian government for letting its borders open to foreign-backed militants to smuggle weapons and enter more forces to their war against Syria.
Turkish government has been one of the open supporters of the war in Syria which started as pro-reform protests in March 2011 and has supported plans to change the Syrian government.
According to Syrian Deputy Foreign Minister Faisal Muqdad, Turkey has let militants from 83 countries to enter Syria and topple the government.
SHI/SHI