中文摘要：

截至2011年5月，BESIII探测器在BEPCII对撞机质心系能量3．773GeV附近采集了2．9fb^-1积分亮度的数据。对这些数据进行物理分析，需要对BEPCII的束流能量（Eb）进行刻度。用预期束流能量计算mKnπ的束流约束质量（mbc），拟合束流约束质量谱得到D介子质量（mD（fu））来刻度邑。对全部ψ（3770）数据进行了束流能量刻度，并检验刻度后的D介子质量和分辨（σD）。结果表明，用刻度后的束流能量得到的D介子质量更接近D介子的真实质量，且分辨得到进一步改善。

英文摘要：

As of May 2011, BESIII has accumulated an integrated data sample of -2.9 fb^-1 around center- of - mass energy of 3. 773 GeV at BEPCII. To analyze these data, it is needed to calibrate the BEPCII beam energy （ Eb）. The expected beam energy was used to calculate the beam constraint mass （ mbc ） of mKnπ combinations and the beam energy was obtained using the fitted mass of D meson （ mo （fit） ） by fitting mbc distribution. The beam energy calibration for all the ψ（3770） data has been performed and the calibrated beam energy has been used to check the mass of D meson as well as the resolution （σD）. The result shows that the fitted mass of D meson with the calibrated beam energy is closer to the true mass of D meson, and the resolution is further improved.