Do you think Voldemort cared about his mother?

I don't think he did. He killed his father and paternal grandparents as a twisted way of 'cleansing' his heritage. He probably hated his mother due to the fact that she married a muggle.

The books give the impression that he doesn't care for Merope at all. He thinks that she was weak, and initially assumes that she must have been a Muggle because she died when he was born. Killing his father was more about avenging his own abandonment rather than hers, and also a twisted way of "cleansing" his part-Muggle heritage.

I think he cared about he because his father left his mother because she was a witch, and Voldemort is very pleased of being related to Sazlar Slytherin.

Sadly, no. I don't think so. Voldemort didn't care about anyone and anything and I don't need any clues to answer it its pretty obvious.