ObjectiveTo understand the epidemic characteristics and regularity of influenza B virus in Guizhou Province, and provide  scientific evidence for the control and prevention of influenza. MethodsResults of reverse transcription polymerase chain reaction(PTPCR) of influenza B virus in Guizhou Province from April 1, 2013 to March 31, 2016 were statistically analyzed. ResultsA total of 1 904 samples were detected influenza B virus by RTPCR, B/Yamagata (By) lineage and B/Victoria (Bv) lineage were 1 215 and 642 respectively. In April 2013March 2014 and April 2014March 2015, the predominant strains of influenza B were both  By lineage, in April 2015March 2016, the predominant strains of influenza B were Bv and By lineages, the epidemic peaks were in winter and spring; there’s a higher positive percentage of influenza B in male, accounting for 56.83%；the highest detection rate of influenza B virus was found in population aged <15 years（70.80%），Bv and By lineages were the highest in the 0~ (42.37%) and 5~ age groups (35.56%) respectively; the main pathogen causing mixed infection was By+Bv (67.65%)，mixed infection with influenza B virus accounted for 95.59%. ConclusionThere are two lineages By and Bv epidemic in Guizhou Province, the epidemic peaks of influenza B are in winter and spring, male cases are higher than female, people under 15 years old are the highrisk group for influenza B, it is of great significance to strengthen the vaccination and surveillance of influenza in low age population.