This research article presents with the 3D steady flow of Casson liquid over an extending surface. Assessment is accomplished in the context of Brownian movement, variable thermal conductivity, higher order chemical reaction and thermophoresis impacts. Similarity transformations are utilized to recreate the boundary layer PDE’s into ordinary differential equations. Due to their extreme nonlinearity, these equations cannot be resolved analytically. So, it was resolved using bvp4c MATLAB solvers. Analysis and discussion are conducted on the effects of significant physical parameters on the flow velocity, temperature, and concentration profiles. Numerical values of skin friction coefficients , Nusselt and Sherwood numbers for various values of Ratio parameter , Thermophoresis parameter, Order of chemical reaction , Schmidt Number , Thermal conductivity parameter, Brownian motion, Heat absorption parameter, Chemical reaction parameter, and Prandtl Number are registered and inspected.