Orient an object on a path

Select the object you want to move along the path curve.
Change the selection mode from object to component.
Click Select by component type in the maya tool bar.
Maya switches to component selection mode.
Click Select by component type: Miscellaneous to display local rotation axes.
Select the rotate tool, and select the local rotation axis of the object.
Rotate this axes so that one axis points in the direction of the front of your object, and another axis points in the up direction of the object.
-click the curve.
Select Animate > Motion Paths > Attach to Motion Path > .
The Attach to Motion Path Options window appears.
Turn Follow on.
When Follow is on, the Front Axis and Up Axis options determine which of the three local rotation axes sets the front and up of the object respectively. See Follow.
Select the axis you chose to represent the front of your object in step 6 as the Front Axis, and select the axis you chose to represent the up direction of your object in step 6 as your Up axis.
Click Select by object type in the maya tool bar.
Maya switches to object selection mode.
With the object selected, -click the curve in your scene that you want as your motion path.
You can now click Attach in the Attach to Motion Path Option window to create your path animation. See Create a motion path using a curve.