how can i closed all open files in Quicktime player

macbook pro, 500gb ,version 10.9.5 ,

all files in open in Quiketime media player how can i closed..whenever i open quicktime all files are open..i have tried to closed by force quit..but whenever i again open quicktime files are still open..

You have basically formed a "poor" habit—i.e., closing apps and assuming they will close any/all open activity windows. The latest versions of Mac OS X now, by default, "remembers" what windows are open when an app is closed. You have three options here:

1) Get in the habit of closing active windows before closing an app to prevent them from re-opening automatically the next time the app is opened.

2) Hold down the "Option" key when selecting the "Quit" menu option (keyboard shortcut "Option-Command-Q") with system preference option in the default mode.

3) Change the default system preference to automatically close active windows in the same manner that older Mac OS X versions did by checking the "Close windows when quitting an app" in the Syeyem Preferences "General" menu.

NOTE: This setting works as a "software switch" for your application's "Quit" menu option. I.e., in the "Unchecked" mode the Option-Quit menu option and keyboard shortcut (Option-Command-Q) tells the system to forget active windows when the app is next opened while the "Checked" option mode tells the system to remember the active windows when using the Option-Quit menu or keyboard shortcut options.

Your choice for settings and/or method of closing apps.