Phytochemical investigation of the decoction of Urtica fissa rhizomes led to the isolation of 23 known compounds. Their structures were identified as medioresinol dimethyl ether （1）, L-pyroglutamic acid methyl ester （2）, nicotinic acid （3）, L-pyroglutamic acid （4）, erythritol （5）, 6-methyl-2＇-deoxy thymidine （6）, 2-methyl-6-（2＇,3＇,4＇-trihydroxybutyl）-pyrazine （7）, 5-hydroxyl-2-hydroxymethyl pyridine （8）, adenine （9）, uracil （10）, thymine （11）, adenosine （12）, inosine （13）, 2＇-deoxyadenosine （14）, 2＇-deoxyguanosine （15）, 2＇-deoxyinosine （16）, uridine （17）, n-butyl-O-β-D-fructopyranoside （18）, di-D-fructose （19）, β-D-fructofuranosyl- α-D-galactopyranoside （20）, his （5-formyl-furfuryl） ether （21）, chlorogenic acid （22）, and 5-hydroxymethyl furaldehyde （23） by spectroscopic methods. In addition, a total of 20 compounds （1-20） were isolated from U. fissa for the first time. Meanwhile, compounds 1, 6, 7, 8, 19 and 20 were isolated from the Urticaceae plants for the first time.
