Abstract: Due to the large amounts of polyphenolics and polysaccharides, the extraction of high quality biochemical molecules like RNA and DNA is always an obstacle to the molecular biology study of cotton. The conventional RNA extraction methods and commercial kits always failed to get high quality RNA or even nothing. Perfect RNA was extracted from embtyogenic callus in cotton uaing Trirol(Invitrogen, # 15596-026) but failed to other tiasues in this study. Here a modified simple protocol was described using guanidinium thiocyanate to extract high quality RNA from cotton with low cost,... ...