At least 70% of human time is spent indoors, and the urban residents even spend more than 90% of their time in the indoor environment, especially infants, the elderly and disabled people, who stay in the room for much longer hours. However, the concentration of air pollutants in indoor environment is generally 2 to 5 times more than that in outdoor environment. Since 1970s, the so-called "Sick Building Syndrome" (SBS) has emerged in some developed countries. This is the performance of the potential problems caused by indoor air pollution. Indoor pollution has become the third generation of pollution in the 21st century. The first generation of pollution was the coal smoke pollution caused by the Industrial Revolution in the 18th century. And the second generation of pollution was the photochemical smog pollution caused by the oil and auto industry in the 19th century. With the rapid development of society and economy, people in modern world have become to pursue high-quality life. The rapid development of China's real estate industry has brought the flourishing of the building decoration industry. However, a survey from the World Bank shows that, every year, China suffers a loss of 10.6 billion dollar caused by indoor pollution. Currently, the healthy problems caused by indoor pollution have become a prominent public health problem. According to its nature, indoor air pollution can be divided two categories: non-biological pollution and biological and microbiological pollution. Non-biological pollutants can be further divided into chemical pollutants and physical pollutants. Chemical pollutants are produced by building materials, decorative materials, household chemicals, combustion products, and so on These substances will emit toluene, xylene, vinyl chloride, formaldehyde and other volatile organic compounds and ammonia, carbon monoxide, nitric oxide, carbon dioxide, sulfur dioxide and other inorganic compounds. All of these chemical substances are on harmful on human health. And physical pollution mainly refers to the radioactive pollution generated by building materials, the noise from indoor and outdoor environment, and the magnetic radiation caused by home appliances. In addition, there is also other pollution caused by dust and respirable particulates. Biological and microbiological pollution refers to the pollution caused by garbage, air conditioning, indoor flowers, pets, carpets, furniture, etc, including bacteria, germs, dust mites, and so on. Indoor pollution can cause various kinds of irritating symptoms and allergic reactions, such as "Sick Building Syndrome" (SBS), "Building Related Illness" (BRI) and "Multiple Allergic Disease" (MCS). The main symptoms include respiratory and eye irritation, allergic pneumonia, allergic rhinitis, asthma, and so on. What's more, it will also affect the immune function and the nervous system.