Masonry building is one o f the commonly adopted structural types o f low-rise civil buildings. The buildings are often susceptible to damage when they are subjected to ground motions o f earthquakes. Damage o f the buildings is in different damage states due to magnitude o f earthquakes. Fragility curves provide a powerful solution tool for seismic vulnerability assessment o f such structures. The use o f fragility curves to evaluate the seismic vulnerability assessment o f a structure was presented in some article researches in the world, however, it was few researches in Vietnam related the vulnerability assessment o f a structure using fragility curves. In this paper, seismic vulnerability assessment o f a low-rise un-reinforced masonry building using fragility curves is investigated by finite element analysis.