The Jayhawks (27-5) advance to Friday's semifinal round, where they will face No. 4-seed Baylor-an 82-74 winner over Kansas State earlier in the day.
Khris Middleton matched a season high with 24 points for the Aggies (14-18).
Elijah Johnson went 8-of-11 from the floor and scored a game-high 26 points for KU. He was one of four Jayhawk players in double figures.
Kansas shot 57 percent overall and 63 percent from behind the arc in the first half to take a 40-28 lead into the locker room.
Texas A&M trailed by early before the Aggies rattled off a 7-point run at the midway mark of the first half to build an early 17-12 lead. Keith Davis began things with a stick-back layup, and Elston Turner soon followed with a jumper. Zach Kinsley then drained a three from the left corner with 10:37 left to end the rally.
The Aggies maintained their lead for a few more minutes before Kansas went on a 13-0 run to take control of the half. Down one with just under eight to play in the half, Elijah Johnson canned back-to-back threes to put KU up five. The Jayhawks would use consecutive threes late in the frame by Tyshawn Taylor to extend the lead to as much as 14.
Kansas was even hotter from the field in the second half, shooting 67 percent in extending its lead to as much as 22. The Jayhawks finished the game 10-of-15 from behind the arc, also a season high.
Keith Davis scored a season-high 8 points, while Ray Turner, Elston Turner and David Loubeau added 8 apiece for Texas A&M.
TEXAS A&M POSTGAME NOTES
- The Aggies fell to 6-16 all-time at the Big 12 Championship ... those six victories, however, have come in the last seven seasons (6-7 record).
- A&M lost a quarterfinal game for the first time since 2007 ... the Aggies had won two straight and fell to 4-2 all-time in that round.
- Kansas (No. 3 AP/USAT) marked the sixth top-5 opponent for A&M this season, a school record.
- A&M's senior class of 2012 (Dash Harris, David Loubeau) finished their careers as one of the winningest classes in school history ... the duo totaled 86 wins, fifth all-time.
- Dash Harris finished his career with 379 assists (7th all time) and 140 steals (8th all time) ... he closes his A&M career as one of just eight players in school history to total 300 assists and 100 steals.
- David Loubeau finished his career with 1,215 points (19th all time) and 581 rebounds (16th all time) ... he ends his Aggie career as one of just 11 players in school history to score 1,200 points and grab 500 rebounds.
- Loubeau finished his career playing in 133 games, fourth all-time at A&M behind Donald Sloan (138), Bryan Davis (135) and Josh Carter (135).
- Khris Middleton posted the 12th 20-point game by an Aggie in Big 12 Championship history ... it was the fifth 20-point game of his career.
- Middleton recorded a season-high 4 steals.
- Middleton's 24 points were a team high ... he led the Aggies in scoring for the ninth time this year and 30th in his career ... Middleton has 983 points and will enter his senior campaign needing just 17 to become the 33rd member of the school's 1,000-point club.
- Kansas became only the second team this year to shoot better than 50 percent from the floor against the Aggies.