E. Kahil, MagdA. Ammar, SamahA. Refaey, Shymaa2023-04-042023-04-042023http://repository.msa.edu.eg/xmlui/handle/123456789/5521The General theory of relativity is one of the most successful theories of gravity. Despite its successful applications, it has some difficulties in examining the behaviour of particles precisely in strong gravitational fields. Bi-metric type theories of gravity are classified as alternative theories of gravity that describing such strong gravitational fields, such as the gravitational field formed at the core of our galaxy. In order to obtain the equations of motion for spinning fluids, we use the Weyssenhoff tensor to express the spin fluid. The equations of motion for spinning fluids are derived using Euler-Lagrange equation. We present the equations of motion for spinning fluids and their corresponding spin deviation equations in some classes of Bi-metric type theories. Also, we obtain equations of motion for spinning fluids and their corresponding spin deviation for a variable mass. Moreover, we extend our study to examine the status of motion for spinning charged fluids and their corresponding spin deviation equations.enBi-metric type theories,Geodesic deviation,Spin density deviation,Charged spinning fluid.MSA UniversityOctober University of Modern Sciences And ArtsArticle