Abstract: The horizontal and vertical resolution of distributed multijnput multi-output (MIMO) radar with coherent processing is studied.The parabolic fitting is used to calculate the mainlobe width of the horizontal and vertical cut of the ambiguity function.Then the mathematical expression for the horizontal and vertical resolution of distributed MIMO radar is deduced.By study on the mathematical expression, the factors that affect the resolution of distributed MIMO radar are investigated, and some guidelines on system design and array design are derived.Finally, the simulations are performed to verify the mathematical expression and theoretical analysis.