Abstract: The properties such as flame resistance,thermal stability,and mechanics as well as the morphology of the fire retardant viscose fiber,which was obtained from graft modification of common viscose fiber,were tested.The results indicate that LOI of the fire retardant viscose fiber is 28.0%,intensity is(2.84 cN/dtex) and short fiber content(SFC) is 9%.TG-DTA shows the fire retardant viscose fiber has absorbed the heat during 200～(300 ℃) with the weight loss of 40%. Compared with common viscose fiber its intensity has decreased by only 2%,and SFC has increased by 3%.Fiber′s longitudinal surface and cross section are comparatively smooth.No visible holes and cracks were observed on the surface of the fire retardant viscose fiber by SEM.This demonstrates that the fire retardant viscose fiber is up to the production requirements in flame resistance and mechanics.