Do I have to download all blocks to see my bitcoin using bitcoin-qt? I saw a youtube video about bitcoin wallet and he said you can't see your bitcoin or send or receive until the bitcoin-qt download all the blocks.
In order for your client to show your bitcoins, you'll at least have to download and process up to the block that validated the transaction with which your money was sent to you. (The client can't show you, what it doesn't know about.)

Bitcoin-QT will allow you to send bitcoins after that, even when it is not synchronized completely yet. Since likely your funds have only been sent to you in the near past, you will have to download almost the complete chain to reach that stage.