“Leather” is a common word in the leather market, was one of the differences between synthetic leather and natural leather used name; in the concept of consumer, “leather” also has a non-false implication. In fact, the leather is leather, it is mainly made of mammalian skin and it. Wide range of leather, types, structures, different quality, price disparity is equal. Therefore, all natural leather is leather catchall, commodity market the previous vague identity. Natural leather by its kind mainly pig leather, cattle, sheep leather for leather, horse and donkey leather and kangaroo leather for leather, otherwise a small amount of fish, reptile leather leather, amphibians such as leather, ostrich leather. Cow leather and leather of cattle hide leather, Buffalo, yaks and cattle yak leather leather; sheep leather into leather of sheep, and goat leather. According to their level, first layer leather for leather and second floor, of which the first layer leather for leather full grain leather and a shave; two-layer leather and pig two layers of leather and cow leather. In the main categories of leather, cattle and sheep leather for leather, the surface flat fine, eyes small, internal structure close tightly, leather has good sense of fullness and elastic, good physical properties. Therefore, the superior cattle leather and leather of sheep leather generally used for high-grade products, its prices are higher in the largest leather category. In the many varieties of leather, full grain leather top, because it is disabled less choice of raw materials processed into leather retaining good natural state on the surface, coating thin, can show the animal skin patterns of natural beauty. It not only wear-resistant, and with good breathability. Slightly corrected leathers fastness, is to use surface light buffing machine leather finishing after grinding, then push forward the patterns produced. Is actually a natural leather with a disability or rough surface had a “facelift”. Almost lost original of this leather surface appearance, finishing layer thicker, wear resistance and permeability less than full grain leather. Two-layer leather, is a thick skin with skin layer, or shave head layer used for full grain leather leather, two-story or film series after finishing processes made of double-layer leather, its poor fastness, abrasion resistance, is one of the cheapest similar leather. Below we describe several common methods: first, feel: the touch surface of leather, such as a smooth, soft, plump, flexible feel are leather; Fase and artificial synthetic leather, rigid and soft and low. Second, see: observation of real leather surface is clear pores, patterns, the pores of the skin have a symmetry of yellow cattle, pores of the skin is coarse and sparse of yak, goat fish squamous pores, pigskin triangle coarse pores, artificial leather, despite the imitation of the pores, but it is not clear. Following to members describes pig leather, and horse leather, and oxhide, and sheep leather of features and identification method: cattle leather surface fine, strength high, most suitable making shoes; sheep leather light, thin and soft, is leather clothing of ideal fabric; pig leather of breathable through water vapor performance good, more for system do underwear and children supplies; horse leather of fiber structure more close, and strength also comparison high, for making skin trousers and boots effect better. In General, leather weight, density, and distribution of pores on the surface is to distinguish oxhide, pig leather for leather, horse and sheep leather main basis. Pig leather: leather surface of pores round and bulky, more inclined to protrude into the leather. Pores are arranged as three groups, leather surfaces rendered many small triangle pattern. Oxhide: leather for cattle and Buffalo leather is called an oxhide, but there is a certain difference between the two. Cattle leather surface pores rounded, more direct into the leather, the pores close and uniform, arranged in irregular, like starry night. Buffalo leather for leather surface pores than the cattle is bulky, pores scarce compared to cattle leather, leather quality more relaxation than cattle leather detailed fullness. Horse leather: leather surface pores are oval, slightly larger than the pores cattle leather, arranged more regularly. Sheep leather: leather grain of pores oval, pores clear, some composed of a set, arrange the fish scaled. Third, the odor: whatever the smell of real leather is leather and leather are human stimulus strong plastic smell. Four, lit: Peel the fiber from the back of real leather and artificial leather, lit, issued a pungent smell, form a lump is leather; issued hair smell, non-hard lumps are leather.