SrTiO₃ the representative of transition-metal oxides in the family of perovskite compounds, which has an irreplaceable role in condensed matter physics for its multitudinous physical properties. SrTiO₃ holds the perfectly centrosymmetric in macroscopic scale in the whole temperature range. At low temperature (< 50 K), SrTiO₃ possesses the quantum paraelectric phase, which is caused by the competing between electric dipole moment and the quantum fluctuations. With ¹⁸O substitution of the ¹⁶O, SrTi¹⁸O₃ undergoes a quantum ferroelectric phase transition below 23K. We use extended X-ray absorption fine structure (EXAFS) to study the local structure of SrTi¹⁶O₃ and SrTi¹⁸O₃. The MSRD of SrTi¹⁸O₃ is increased comparing with SrTi¹⁶O₃ below Tc (23 K), which means the correlated movement between Ti and O is reduced with ¹⁸O substitution. The PDF of SrTi¹⁶O₃ at 004 K shows no splitting of the Ti-O bond, but in SrTi¹⁸O₃ clear Ti-O bond splitting are observed, which indicates the triumph of the electric dipole moment against the quantum fluctuation. The small non-centrosymmetric local structure of SrTi¹⁸O₃ and low-temperature phase transition can be used to manufacture electronic devices with special functions, such as radiation-hardness of ferroelectric memories, and array radar devices.The same experiment is also conducted for other doped quantum paraelectrics Sr_1-xCa_xTiO₃, Ag_1-xLi_xTaO₃, and Cd_1-xCa_xTiO₃. The same MSRD variation is observed.