L-carnitine calcium fumarate and its preparation and applications are disclosed in the present invention. Having good water solubility as well as better and stronger nutritious and treating functions than the corresponding inner salts, the L-carnitine calcium fumarate as proposed having the advantages of being non-hygroscopic, stable in chemical property, and suitable for oral administration. A preparing method is as follow: fumaric acid is suspended in water and calcium base is added. The resulting mixture is heated up to 70~90° C. and kept under stirring for 2~8 hours, and then concentrated under reduced pressure. The resulting dried substance is added into ethanol, and the mixture is vigorously stirred. The inner salt of L-carnitine is added, and the mixture is reacted for 1-6 hours at 60~70° C. and then cooled for 2~8 hours. L-carnitine calcium fumarate is obtained by filtration.
