There is a rich literature on whether foreign aid can improve economic growth in the recipient country, yet few study the motivation of aid donors. Can the allocation of foreign aid be a strategic tool to improve bilateral political relation as many newspaper articles have argued? This paper seeks to answer this question accounting for the dynamic interaction between foreign aid and political relation in the panel vector auto regression. Using bilateral data from 1972 to 2013, we find evidence that bilateral foreign aid weakens bilateral political relation and that donors allocate more foreign aid to countries with better political relation. The negative impact of foreign aid on political relation is weaker when the donor and recipient countries are from the same legal system or were in colonial relationship before.