In 2015 the LHCb collaboration reported observation of significant J/psi p pentaquark structures in the $\Lambda_b^0 -> J/\psi p K^-$ decay using Run 1 data. This is a major turning point in the exotic baryon spectroscopy. At this seminar, an update on this pentaquark study with full Run 1 and 2 data collected by the LHCb detector will be presented. New pentaquark state and more complex structures are observed. Possible interpretation will be also discussed.