To prepare a medical electrolyte liquid, capable of being produced aseptically from sea water by a simple production process at a low cost and further containing rich mineral components contained in the sea water, and to provide a method for producing the same.

The medical electrolyte liquid is obtained by removing foreign materials such as viruses, bacteria by passing the sea water through a membrane separation means, but cleaning so as to remain the mineral components contained in the sea water, blending aseptic distilled water to obtain diluted, cleaned sea water and adjusting the osmotic pressure of the diluted, cleaned sea water to a prescribed value. The medical electrolyte liquid can be used as physiological saline adjusted to have an equivalent osmotic pressure with human body fluid, various transfusion, dialyzing liquid, or the like.