LBC is the lightweight block cipher proposed by Kapalova et al. in 2023. The block size is 64 bits, the secret key size is 80 bits, and the number of rounds is 20, respectively. The designer analyzed the avalanche effect and evaluated the security against differential and linear cryptanalysis. On the other hand, the security against integral cryptanalysis, one of the most powerful cryptanalyses on block cipher, has yet to be evaluated. In this paper, we evaluated the security of LBC by applying integral cryptanalysis. We investigated the integral characteristics with the bit-based division property using Mixed Integer Linear Programming (MILP). Consequently, we found that LBC has the 18-round integral characteristic using the 60-th order differential. Exploiting the discovered 16-round integral characteristic using the 48-th order differential, the integral attack on the full-round LBC can be efficiently performed with \(2^{50.8}\) blocks of chosen plaintext and \(2^{51.4}\) times of encryption operation. Then, we improve the round function of LBC and discuss its security against integral attack.