Since you haven't specified the wallet you used and how you lost your bitcoin, I can only give you some general suggestions.
Scan your computer for malware now.
Don't download or run suspicious program.
Don't click links in emails.
Enable 2FA if you are using a web wallet.
thank you ,i now Storage all my coins on the exchange,like:OKCOIN.
i don't want to update the large number of blocks data.
Don't store your coins on an exchange, if that exchange pulls a MtGox, you're screwed.