Ensuring the grain supply-demand balance and achieving grain security had been the main tasks for the government of Bangladesh. On the supply side, Bangladesh's supply of grain products has increased substantially, with an average annual growth rate of 1.99 million tons in 1998-2018. Domestic grain production, especially rice production, accounted for the largest proportion in its structure. However, under the constraints of resources and environment, imports and international aid were needed to ensure a stable and sustainable grain supply. On the demand side, Bangladesh's demand for grain products continued to grow at an average annual rate of 2.09 million tons and its structure was constantly diversified. In recent years, domestic grain production has fully met the grain demand for food use, but the overall grain supply dependence on foreign gradually increased. From the analysis of the influencing factors, the grain supply, especially the domestic production of rice and maize, had the greatest impact on the balance of grain supply-demand in Bangladesh. Moreover, multiple cropping index, chemical fertilizer application per hectare and irrigation rate were the three main factors affecting grain production. As a typical agricultural country, Bangladesh's grain security was faced with challenges, such as high population density, insufficient cultivated land resources, international grain trade and frequent natural disasters. It is suggested that its government should strengthen scientific and technological research, adjust agricultural structure, improve the efficient utilization of agricultural resources and grain circulation systems, and balance the grain demand between food use and indirect use, so as to achieve complete grain self-sufficiency and overall grain security.