The incident happened around 2:40 p.m. in the Los Angeles suburb of Sierra Madre, located in the foothills next to the Angeles National Forest.
The mother bear, trying to protect her cub, went after the small dog to protect her baby.
Sierra Madre Police Chief Jim Hunt told KTLA the man, in an attempt to protect his dog, kicked the mama bear who then slashed his calves and bit the back of his right knee.
The man, aged in his 50's, was taken to the hospital but was expected to be ok. The dog was taken to a veterinarian and also did not sustain any serious injuries.
Fish and Wildlife officers tranquilized the bears and took them away.
The department said there is increased black bear activity at this time of year but that the bears rarely pose a threat to public safety or to dogs and cats.
The Associated Press contributed to this report.