BM@N - Baryonic Matter at Nuclotron is a fixed target experiment that is part of NICA (Nuclotron-based Ion Collider fAcility). This experiment is dedicated to study ion collsions to strudy properties of the equation-of state (EoS) of dense nuclear matters. This EoS plasy crutioan role for understanding nature of neutron stars and collapses of supernovae. Data taking in experiment require continuous monitoring of quality. Therefore it’s important to have an on-line system for monitoring quality of experimental data. Currently was implemented fast decoding algorithm and monitoring system to BmnROOT. System consists of two parts – first is RawDataDecoder that get raw data from DAQ system and decode into ROOT format. Second part is BmnMonitor that read data from ZeroMQ socket and fill histograms. Histograms are made accessible by ROOT ThttpServer. Lighttpd web server serving as local proxy makes it available for for outside http requests.