Ptychobarbus dipogon is one of the most important endemic fish species in the upper and middle reaches ofthe Yarlung Tsangpo River. However, P. dipogon populations have declined sharply in recent years and their biology ispoorly understood. To better understand the biology of P. dipogon and their relationship with management, we describethe relationships between standard length and body weight and age, verify annual growth of lapilli otolith annuli, andestimate P. dipogon growth. The age structure and growth characteristics of P. dipogon were investigated by examining956 specimens collected in the Yarlung Tsangpo River during 2008–2009 and 2012–2013. Standard lengths were146–569 mm in females, 167–506 mm in males, and 78–297 mm in some undetermined specimens. Otolith annuliformed from March–June each year. Estimated ages were 3–24 years in females, 3–13 years in males, and 2–6 years inundetermined specimens, respectively. The standard length–body weight relationships were described by W= 2.494 ×10−5Ls2.877 for females and W= 2.790×10−5Ls2.856 for males. The von Bertalanffy growth equations were: Lt= 606.9[1−e−0.114(t+0.163)] and Wt=2538.4[1−e−0.114(t+0.163)]2.88 for females and Lt=496.3[1−e−0.162(t−0.018)] and Wt=1391.1[1− e−0.162(t−0.018)]2.86for males. The growth inflexion points were 9.1 years for females and 6.5 years for males, and the corresponding standardlengths and body weights were 396.0 mm and 743.6 g for females and 322.5 mm and 406.3 g for males, respectively.Our results show that the P. dipogon population tended to be younger. Climate changes, biological invasion, andover-exploitation could be the main factors threatening P. dipogon stocks. The sound management policies proposed inthis study should be implemented to conserve P. dipogon populations.