30 years of BES physics : proceedings of the symposium Institute of High Energy Physics Beijing China 5 6 September 2019 BES the Beijing Spectrometer began its first groundbreaking physics run in 1989 already 30 years ago! This was the first high energy physics experiment in China and has been unique throughout the world for its thorough and extended coverage of the tau and charm energy region. Over these 30 years the BES detector has been steadily improved upgrading to BESII in 1998 and to BESIII in 2008. And over the same period the collaboration has evolved from including about 150 members from 10 institutions in China and the United States to about 500 members from 72 institutions in 15 countries. The physics program too has extended from light hadron spectroscopy tau and charm physics to the discovery of exotic charmoniumlike states precision tests of the Standard Model of particle physics and searches for new physics beyond the Standard Model. This special volume collects the proceedings of the symposium held at the Institute of High Energy Physics Beijing in celebration of the 30 year great achievements of the BES BESII and BESIII experiments. Written by many leaders of the BES collaborations these proceedings documented the early days of the BES experiment the achievements of all of the BES experiments and the future physics program at BESIII Beginnings of BES experiment Zhipeng Zheng From BESI to BESII Fred Harris The BES publications policy J.M. Izen The first tau mass measurement by the BES collaboration Walter Toki Direct measurements of the weak decay constant fDs (fD) and the Ds(D) branching fractions to μνμ φπ eX φX (μνμ) at C.M. energy of 4.03 GeV C.C. Zhang The initial ψʹ physics program at the BES experiment Chang Zheng Yuan Initial ψ(3770) and its related physics at the BES experiment G. Rong The first permanent international computer network connection between China and the USA R.L.A. Cottrell and R. S. Xu BESII vertex chamber and MDC II feedthroughs R.L. Malchow BEPCII BESIII Hesheng Chen From BESII to BESIII Weiguo Li The European contribution to BES(III) W. Gradl JINR and Russian groups in BESIII A. Zhemchugov The initial XYZ program at BESIII (2010 2014) R.E. Mitchell C.Z. Yuan High energy physics at IHEP Yifang Wang Light hadron physics at BES experiment S.S. Fang Charmonium and charmonium like states Kai Zhu Charmed meson physics Hailong Ma τ physics at BESIII Jianyong Zhang R measurements and QCD studies at the BES experiments Guangshun Huang Nucleon hyperon physics at BES Stephen Lars Olsen New physics program of BES Dayong Wang The BESIII and its upgrade M.Y. Dong Selected BES publications Epilogue by Minghan Ye.