RNAfixer is a aqueous and nontoxic tissue-holding liquid, which canin situ stabilize and protect RNA under non-frozen situation by rapid infiltrating fresh tissues and not affect RNA yield and integrality. Hence, RNAfixer eliminates inconveniences to flash freeze samples in liquid nitrogen or take samples from different places. When fresh tissues immerged into RNAfixer, RNA can be stored up to a day at 37℃, a week at 25 ℃, a month at 4℃ and a long term at -20℃ or -80℃. RNA virus (such as HCV and HIV) is stable up to a month at 37℃ in RNAfixer.