Among 30 plant species examined, the PPi‐phosphofructokinase (EC 2.7.1.90) was found in leaves of 21 plants. Some of the plants exhibit no activity of ATP‐dependent phosphofructokinase but display only activity of PPi‐phosphofructokinase. A partly purified preparation of PPi‐phosphofructokinase with specific activity of 8.4 Hmol (mg protein)−1min−1was obtained fromSanseviera trifasciataleaves. The enzyme is restricted to the cytoplasm, it exhibits pronounced substrate specifity, requires Mg2+ions, is inhibited by AMP, PEP, methylenediphosphonate and stabilized by mercaptoethanol. At pH 7.8 with 1.5 mMMgCl2the following KMvalues were observed: pyrophosphate, 0.58 mM; fructose 6‐phosphate, 0.8 mM. The KMvalues for substrates of reverse reaction (pH 7.3; 2 mMMgCl2) are of the same order of magnitude: 0.83 mMfor fructose 1,6‐diphosphate, and 0.14 mMfor orthophosphate. The molecular weight of the studied enzyme is about 125 000 dalton as estimated by