In textile industry, many attempts have been made for increasing the resistance of textiles against the flame and heat. Among different fibers, acrylics are very sensitive to thermal treatments. Nanotechnology is a novel science applied in different sciences. Nano particles possed at least one dimension in nano scale. Nanoclay has been fabricated from silicate layers with micro-scale surface area and nano-scale thickness. Nanoclay particles are mainly used in nano composites and can increase the mechanical strength, thermal stability and barrier effect. These nano composites are used in food industry, aerospace science, medicine, etc. In this thesis, the flame-retardancy properties of acrylic fabrics using nanoclay powder, Sodium Montmorillonite, have been investigated. Regarding this objective, nanoclay particles were used on acrylic fabrics at different concentrations using textile finishing methods. The flammability properties of treated samples were tested usuing flammability tester machine adapted to ASTM 1230 standard. .