D介子衰变到含有中性K介子的末态时，实验上只能通过末态含有KS和KL粒子的过程进行测量。一直以来，人们假设D介子衰变到含有中性K介子的末态时，中性K介子总是等比例地，即各占50%衰变到KS和KL, 因而分支比总是用含有KS的末态进行归一，因为实验上对KL的探测是极其困难的。.近年来的理论与实验研究证实，由于Cabbibo允许道与双重Cabbibo压制道之间存在干涉，会造成衰变末态中KS和KL粒子的数目不等。随着实验的发展，尤其是以BESIII为代表的新一代探测器与加速器的成功建造与运行，使我们可以系统地对这一问题进行研究。对BESIII目前所取的大约2.9pb-1的psi(3770)数据进行仔细的分析与研究，我们预计可以在strong phase， CP破坏以及DDb混合等方面取得大的进展或突破。

D mesons have large decay branching fractions to final states contain one neutral kaon. The neutral kaons can be measured experimentally by detecting KS and KL. In the past years, the branching ratios of D to neutral kaon final states are normalized by using that of D to final states contain KS,since the detection of KL is a tough challenge to experiment, 50% to KS and KL final states are assumed..The interference of Cabbibo allowed and double suppressed decays for final states contained neutral kaon may cause the difference between the decay branching ratios.of D to KS X and D to KL X. After the successful built and runing of new generation detector and accellerator, such as BESIII, people may study this question systematically. We are expected to make great progress and achieve important results in strong phase, direct CP violation,and neutral D meson mixing by analyzing the huge data psi(3770) sample collected at BESIII.