Managing your Chat History
Skype archives your chats for you and stores them locally on your computer, if you have enabled this option. Chat histories are not stored anywhere on the Skype network. In other words, no one else will ever be able to see any of your chat histories except you and the person you are chatting with. Chats are archived as a convenience to you, so that you can easily keep track of your chat conversations on Skype, think of it as sent mail for Skype.
To enable or disable this option go to: Skype -> Preferences -> Chat and select your choice of chat history settings.
To view archived chat sessions for specific contact, select the contact from your Contacts List and go to: Contacts -> View Chat History. A browser window will open showing your previous chat sessions with the selected contact.
You can clear your chat history by selecting “Delete All Chat Messages” under the “Chat” menu.
Please note that calls are not archived and therefore won’t be shown in chat history.
How do I backup my chat history?
Skype archives your chats locally on your computer, if you have enabled this option. If you want to backup your chat history or move it to another computer you can find it in a folder with the same name as your Skype Name in “username/Library/Skype”