>Is it 100% safety to buy with credit card trought Internet?

No, it's not 100% safe. Even if the site uses Secure Socket Layers (SSL), the database can still be hacked, the site may not make full use of SSL for all of your personal information, and a host of other things can comprimise the safety of your credit card number. That being said, I use the Internet for all kinds of shopping. It may not be 100% safe, but it's close enough to suit me.

The reason I say "it's close enough" is because people don't think twice about handing their credit card to a restaurant waiter. The waiter walks off to a mysterious room out of sight, and may be gone for 5 minutes or more, which is more than enough time to scribble down your credit card information. Next thing you know, L. L. Bean charges start showing up on your card statement.

This is but one example of how credit card usage that you take for granted can be comprimised. A site which has taken the proper precautions is no more dangerous than handing your credit card to the hotel clerk for them to make an impression of the card as a deposit (from which they scribble down the card number after you go to your room).