Hello dongtso

Welcome to the Community Earth BBS and to Google Earth

In your post above you have included a photo.. All that you have done there is correct.

Below I shall add some Help links and Also a link to Google Sketchup

Google Sketchup

To add a placemark to your posts you need to check out the following 2 links to help you on your way.

Lrae's Basic Training, Placemarks and Overlays

and

Lrae's Advanced Training, Description Balloons (creating, images, links, text)