Women are one of the special and large customers of the textile industry. The female customers have many types of products as color, kind of clothing than male customers. Although there are many types of products, women's underwear is also the most interested product. Because this is an extremely special and sensitive product. Although it is an underwear, this is also a product that needs very high aesthetics. It is a sensitive with skin of customer and especially affects women's health. Whose used the product unsafe, they can easily get infections and allergies. The underwear is regular product, they wash frequent, so underwear must have the color fastness when washing to ensure the aesthetics and service life of the product. The product must have a long life cycle, clothes must be long-lasting, colorfastness,…. In this article, we have studied the structural characteristics of the fabric, the color fastness and shrinkage of the fabric after washing 50 times, the elasticity of the fabric, pilling of fabric. The products were purchased from local markets in Hanoi and a product of company in Hanoi.