RNase TCS isolated from plant Trichosanthes Kirilowii Maxim has a highuracil-specific activity. In the absence of urea and under conditions of PH3.5, 50℃, it cleaves almost exclusively and uniformly at -NP ↓ U-. Inconjunction with RNase T1, U₂ and limited alkaline hydrolysis, the RNase TCS is useful in direct enzymatic RNA sequence analysis.