The widow of ROBERT KARDASHIAN released some of his journals to "In Touch Weekly", and if what's in them is true, this could be a P.R. nightmare for KRIS JENNER.  The journals were supposedly written in 1989 and '90.  And in one entry, Robert talks about his then-wife beating up their daughter KIM, who would have been 9 or 10 at the time.  Robert said, "Kris was kicking and beating her and said she was going to kill [Kim]!  Kim was hysterical."

In another entry, Robert wrote about how Kris would leave for DAYS to mess around with Todd Waterman, a guy she has since admitted to cheating on Robert with.  He said, "She doesn't leave a number in case of emergency.  She doesn't care!  She left [the] kids and screwed all night!"

Apparently, Kris also skipped a Christmas with the family, "Kris couldn't get her act together.  I was home alone with 4 kids."

Kris's rep says, "We have no knowledge of these diaries existing and these accusations are ridiculous and not true."

(Robert and Kris were married from 1978 to 1990.  He died of cancer in 2003.)