Insufficient diffusivity data of Mg alloys especially for some key elements is hindering the computational design of high performance Mg alloys using the ICME (Integrated Computational Materials Engineering) approach. Experimental diffusion profiles were collected using both liquid-solid diffusion couples and diffusion multiples at multiple temperatures for each system. A forward-simulation analysis was applied to the diffusion profiles to reliably extract diffusion coefficients of important alloying elements in Mg alloys, including Al, Zn, Sn, Ca, Mn, Y, Gd, Li, Nd and Ce. Together with the critically evaluated literature data, a mobility database for Mg alloys is being developed. The diffusion coefficient (mobility) database fills the gap in diffusion kinetics of Mg alloys systems and will help accelerate the development of Mg alloys.