We have discovered and developed new nonlinear optical crystal CsLiB_60_<10> (CLBO). In this review, we show the basic concept of the borate crystals and how we could discovered CLBO. The crysal structure, phase diagram, growth method, mechanical properties and optical properties of CLBO are briefly summarized. The superlarge CLBO crystal with demensions of 14×11×11cm^3 was obtained by the top-speeded solution growth method. Fouth harmonic and fifth harmonic generations of the 1,064μm Nd: YAG laser radiation with type-I phase matching can be realized in CLBO crystal.