James connected on 11 of 17 shots from the field. In the third quarter, James hit his first five shots helping Cleveland build the lead to 33.
The win extended the Cavaliers' season-high winning streak. Meanwhile, Memphis, with the league's worst record, lost its second straight and eighth in the past nine.
Rudy Gay led Memphis with 24 points, while Pau Gasol finished with 23 points and 10 rebounds. Stromile Swift added 11 points.