When creating a 3D sketch, by default, you sketch relative to the default coordinate system in the model. To switch to one of the other two default planes, click the desired sketch tool, and press the Tab key. The origin of the current sketch plane is displayed.
You can also create 3D sketches using a 3D sketch plane.
To change the coordinate system for your 3D sketch, click the desired sketch tool, hold down the Ctrl key, and click a plane, a planar face, or a user-defined coordinate system.
If you select a plane or a planar face, the 3D sketch planes rotate so that the XY sketch plane is aligned with the selected item.
If you select a coordinate system, the 3D sketch planes rotate so that the XY sketch plane is parallel to the XY plane of the coordinate system.