In this paper, we consider Keller-Segel chemotaxis coupled with the Navier-Stokes in three-dimensional. mechanism involving a diffusive partial differential equation. Which describes the dynamics of oxygen diffusion and consumption, chemotaxis, and viscous incompressible fluids. The cells and chemical substances are transported by a viscous incompressible fluid under the influence of a force due to the aggregation of cells. We use the energy method to prove the existence of local solutions in bounded domains of R^3 for small initial................... Keywords: ...............Chemotaxis system, Energy method, nonlinear diffusion.