Click Coordinate
System 
on the Reference Geometry toolbar, or click
Insert,
Reference Geometry, Coordinate
System.
Use the Coordinate System PropertyManager to create the coordinate system.
You can define a coordinate system for a part or assembly. Use this coordinate system with the Measure and Mass Properties tools, and for exporting SolidWorks documents to IGES, STL, ACIS, STEP, Parasolid, VRML, and VDA.
To create a coordinate system:
Click Coordinate
System on the Reference Geometry toolbar, or click
Insert,
Reference Geometry, Coordinate
System.
Use the Coordinate System PropertyManager to create the coordinate system.
You can amend your selections:
To change your selections, right-click in the graphics area and select Clear Selections.
To reverse the direction
of an axis, click its Reverse Axis Direction
button in the PropertyManager.
Click OK 
.
You may need to locate a coordinate system where there are insufficient entities available to define the coordinate system. In this case, you can define a coordinate system someplace on the part or assembly that does provide the entities you need. Then you can move the new origin to the desired location. The new location must contain at least one point or vertex.
To translate a coordinate system to a new location:
Click Coordinate
System or Insert, Reference Geometry,
Coordinate System.
Define the coordinate system at a location on the part or assembly that provides the entities you need to control the angle and direction of each axis.
Click in Origin, then select the point or vertex to which you want to translate the origin.
Click OK. The origin moves to the location that you selected.
When
you create a coordinate system, it is a good idea to give it a meaningful
name to explain its purpose. Click-pause-click the coordinate system’s
name in the FeatureManager design tree and enter a new name.
To toggle the display of coordinate systems:
Click View, Coordinate Systems.
To hide or show individual coordinate systems:
Right-click the coordinate system in the graphics area or in the FeatureManager design tree.
Select Hide or Show.
Individual
coordinate systems always are highlighted when you select them, even when
hidden.