This paper applies analytical and numerical methods to study possible causes of the formation and translation of North Brazil Current retroflection eddies. It shows that the dynamic response of the equatorial western boundary of the Atlantic Ocean to either a remote forcing which is represented by an incoming Rossby wave packet that deepens the equatorial thermocline, or to the wind forcing over the tropical Atlantic Ocean can result in northwestward translating eddies up the coast of Brazil. The numerically simulated eddies closely resemble the features of the observed North Brazil Current retroflection eddies. The formation mechanism of these eddies has to do with the short equatorial Rossby waves (which can be generated by the said kinds of forcing), nonlinearity, and the boundary effect. The translation mechanism of these eddies is related to the nonlinear effect caused by the eddies' interaction with the boundary and to the variation of the Coriolis parameter with latitude.