{basePath}

echo Yii::app()->basePath;

path/to/protected

{like} /YiiBlog/protected

{theme baseUrl}

echo Yii::app()->theme->baseUrl;

path/to/themes/themeName

{like} /YiiBlog/themes

{request baseUrl}

echo Yii::app()->request->baseUrl;
path/to/projectFolder
{like}/YiiBlog

{Link ^ ^} you can find some url control in Yii from here -> Click Me