We have investigated effects of an applied uniaxial strain on nuclear spin coherence in an n-(110) GaAs/AlGaAs quantum well by optically detected nuclear magnetic resonance (ODNMR). The ODNMR line widths associated with the quadrupolar splitting increase with the applied external strain because of the increase of inhomogeneous broadening. It is found that the phase decoherence of nuclear spin ensemble for the transition between quadrupolar-split two levels vertical bar-1/2 > and vertical bar+1/2 > is suppressed with increasing the quadrupolar splitting. (C) 2014 The Japan Society of Applied Physics