Epoxy resin is a kind of commonly used high polymer material, it has good physical quality and chemistry, apply extensively at the domain such as material of coating, adhesive, electron, aerospace, housing materials. Among them, density is property of a of epoxy resin important physics, also have important sense to its application. The article will introduce the density of epoxy resin and its influencing factor, discuss density to use medium function in epoxy resin. One, the density epoxy resin of epoxy resin is compound of a kind of high polymer, its density is normally between 1.05-1.25 G/cm³ . Do not have different density with phyletic epoxy resin, for example, the epoxy resin thickness that small element measures is inferior, the epoxy resin thickness that high polymer measures is taller. In addition, the density of epoxy resin still gets the influence of the other factor such as its solidify agent, filling. 2, the factor that affects epoxy resin density 1. The molecular volume that the element measures epoxy resin is higher, its density is higher also. Because the element measures the interaction power between tall epoxy resin element,this is stronger, the element is arranged more close together, density is so bigger also. 2. Solidify agent the solidify agent of epoxy resin is another when affect its density main factor. Different solidify agent is different to the density influence of epoxy resin. For example, contain amino solidify agent to be able to make the density of epoxy resin increases, and the solidify agent that contains hydroxyl can make its density is reduced. 3. Filling filling is the main component of epoxy resin. The filling of different sort is different also to the density influence of epoxy resin. For example, black lead filling can make the density of epoxy resin is reduced, and silicate filling can make its density increases. 3, density uses medium function in epoxy resin 1. Reason of a when the content reason that affects epoxy resin pledges density is epoxy resin important thing is simple, closely related the other physics property of it and epoxy resin. For example, density jumps over big epoxy resin to have higher intensity and hardness normally, and the epoxy resin with lesser density has better impact resistance and tenacity normally. 2. The treatment function density that affects epoxy resin still can affect the treatment performance of epoxy resin. The epoxy resin with lesser density has better liquidity and besmear Fu property normally, easy treatment becomes thinner coating or film. And the epoxy resin with bigger density has better fill performance normally, suit to be used at the application such as fill and agglutinate. 3. The cost density that affects epoxy resin still can affect the cost of epoxy resin. The epoxy resin with bigger density needs to use more material to come normally the product with same preparation, cost is accordingly higher also. Contrary, the epoxy resin with lesser density criterion normally more economy is substantial. The density of conclusion epoxy resin is a main physical character, it gets the influence of a variety of elements. Understand these elements to be able to be helped to the influence of epoxy resin density we choose better and use epoxy resin, realize better performance and cost effectiveness.