can u check my purchase history
if i want to check my purchase history,i must install itunes first??
iPhone 3GS, iOS 6.1.6
If you want to view your account's full purchase history then yes, you can only do so by having iTunes installed on your computer : log into your account on your computer's iTunes via the Store > View Account menu option, you should then see a Purchase History section with a 'see all' link to the right of it. Click on that and you should then see a list of your purchases.
iTunes download : http://www.apple.com/itunes/download/
On your iPhone you can only view a cut-down version (the last 90 days) via http://reportaproblem.apple.com - that site also allows you to contact iTunes Support (these are user-to-user forums) if you have a problem with a purchase.