Lattice dynamics,electronic and lattice contributions to dielectric and piezoelectric responses of BaTiO₃/SrTiO₃(1:1)(BTO/STO 1:1) 10-atom superlattice with Ba/Sr [110] and [111] ordering were investigated with first-principles calculations. We explored ground structure from the highest phase by successively freezing in unstable polar modes. We found that ground structure are in Pm and R3m symmetry,respectively. Lattice contributions to dielectric and piezoelectric tensor coming from individual atoms and individual modes were explored. O and Ti atoms provide extraordinary great contribution to lattice dielectric and piezoelectric responses. On the other hand,great dielectric and piezoelectric tensor are mainly due to low frequency phonons. Especially,for BTO/STO(1:1)superlattice with Ba/Sr [110] ordering,ε₁₁is mainly due to A' phonons with ω_λ=49 cm^-1.