Explorations of new types of borates are important because of their promising application in diverse fields. A new bismuth-containing boroselenite, Bi-2[B-2(SeO3)(6)], has been obtained through high-temperature solid-state reaction in a closed system. Bi-2[B-2(SeO3)(6)] possesses a zero-dimensional [B-2(SeO3)(6)](6-) anionic group that does not belong to any types of reported boroselenites. Besides, Bi-2[B-2(SeO3)(6)] is the first boroselenite with lone-pair electrons containing a metal ion as the countercation. More interestingly, on the basis of the first-principles calculations, this compound displays a large birefringence (0.090) at 1064 nm.