The　seismic　performances　of　28　geometrically　similar　concrete　shear　walls　reinforced　with　basalt　fiber-reinforced　polymer　(BFRP)　bars　were　simulated　using　a　mesoscale　modeling　approach.　In　the　modeling,　concrete　heterogeneities　were　explicitly　described,　and　the　interaction　between　BFRP　bars　and　surrounding　concretes　was　also　considered.　The　influences　of　shear　depth,　shear　span　ratio　and　vertical　reinforcement　ratio　on　the　failure　of　shear　walls　were　investigated.　The　simulation　results　indicated　that　with　the　increase　of　shear　depth,　the　failure　modes　were　basically　the　similar,　while　the　nominal　shear　strength　decreased　significantly,　namely,　the　presence　of　size　effect　was　demonstrated.　The　shear　wall　would　exhibit　different　failure　modes　as　the　shear　span　ratio　varies.　Moreover,　it　was　found　that　the　vertical　BFRP　bar　presented　an　ignorable　influence　on　the　failure　mode,　while　the　increase　of　vertical　reinforcement　ratio　would　obviously　improve　the　shear　strength　of　BFRP-RC　shear　wall.　Finally,　the　present　simulated　shear　strengths　were　compared　with　some　available　size　effect　laws　and　some　codes.