Struts and Mount

This might be a silly question to some but im new at this, and i was wondering when i change my strut mount, is it neccessary to change my strut bar also? should i change both or can i go by changing the strut mount alone? thank you

By "strut bar", are you referring to the round bar that extends between the upper strut mounts? No reason to replace that unless it has been bent or otherwire damaged.