In January 2008, at the 6th Gibtelecom Chess Festival in Gibraltar, Bu came joint first scoring 8/10 (+7−1=2; Elo performance 2834) but lost on the two game blitz play-off tie-break to Hikaru Nakamura. In April 2008, Bu competed at the Russian Team Championships in Dagomys, Sochi for the team Shatar-Metropole (Buryatia), where he achieved a score of 6½/10 (+3−0=7) and a performance rating of 2771. In his super-tournament debut in Sofia, Bulgaria at the Grand Slam M-Tel Masters (category 20) tournament on May 7–18, 2008, he came fifth out of six players (Levon Aronian, Ivan Cheparinov, Vassily Ivanchuk, Teimour Radjabov, Veselin Topalov) having scored 3/10 (+1−5=4; Elo performance 2594).
He competed at the Inventi Grandmaster Tournament in Antwerp, Belgium on 23–31 August 2008. He won the tournament with a score of 7/9 (+5−0=4) and a performance rating of 2748.
In September 2008, he competed at the 5th Russia v China Match in Ningbo where he scored 2½/5 with a performance rating of 2707 for the men's team (with Wang Yue, Wang Hao, Ni Hua, Li Chao).
In December 2008, he came third out of six at the Pearl Spring chess tournament in Nanjing with 5/10.