The density of blood is usually between 1.052-1.060. The normal value of blood density is about 1.052-1.060 for an average male and 1.049-1.056 for an average female. 1. Blood is composed of plasma and blood cells: plasma contains water, inorganic salts, fibrinogen, albumin, globulin, enzymes, hormones, various nutrients, metabolites, etc.; blood cells are divided into three categories: red blood cells, white blood cells, platelets. The density of blood is related to the number of blood cells contained and the composition of plasma, and usually varies with the number of blood cells. 2. In determining the density of blood, the relative density of blood is commonly used. The relative density of blood is the ratio of the weight of the same volume of water as 1, blood to the same volume of water. 3. In determining the density of blood, the blood drops in a certain test tube containing copper sulfate solution, directly with a densitometer to measure the blood density.