The measurements of the relative strong-phase parameters between $D^0$ and $\bar{D}^0$ in the decays $D^0\to K_{S,L} \pi^+\pi^-$ are presented by using 2.93 fb$^{-1}$ of data collected at $\sqrt{s}$=3.773 GeV by the BESIII detector. The results can provide the key inputs in model independent measurments of CKM angle $\gamma$.
Using these parameters, the associated uncertainty on the Cabibbo-Kobayashi-Maskawa angle $\gamma/\phi_3$ is expected to be approximately
a factor of three smaller than that from the CLEO measurements, for an analysis using the decay $B^{\pm}\rightarrow DK^{\pm}$, $D\rightarrow K^0_S\pi^+\pi^-$, where $D$ represents a superposition of $D^0$ and $\bar{D}^0$ states.