Let k and n be positive even integers. For a cuspidal Hecke eigenform h in the Kohnen plus space of weight k − n/2 + 1/2 for Γ 0 (4), let f be the corresponding primitive form of weight 2k − n for SL 2 (Z) under the Shimura correspondence, and I n (h) the Duke-Imamoḡlu-Ikeda lift of h to the space of cusp forms of weight k for Sp n (Z). Moreover, let φ In(h),1 be the first Fourier-Jacobi coefficient of I n (h) and σ n−1 (φ In(h),1 ) be the cusp form in the generalized Kohnen plus space of weight k − 1/2 corresponding to φ In(h),1 under the Ibukiyama isomorphism. We then give an explicit formula for the Koecher-Maass series L(s, σ n−1 (φ In(h),1 )) of σ n−1 (φ In(h),1 ) expressed in terms of the usual L-functions of h and f .