For somehow, I can't get GStream installed from the Synaptic Package Manager. Instead of it, there steps will be helpful:
1. sudo apt-get install libgstreamer0.10-dev
With this step done, you will be able to find this folder: /usr/include/gstreamer-0.10/. Compile your own code is possible so far. But still sometimes people need APIs from gst/app. Let's get it done by step 2.
2. sodu apt-get install libgstreamer-plugins-base0.10-dev
Your environment is ready to develop GStreamer based program, enjoy it!