The present invention relates to a 
coumarin compound that is used for analysis of enzymatic activity and 
enzyme inhibitor screening. The compound has a structure formula as shown in the right; wherein, R<1> is an H atom, ester prepared from 
hydrogen of OH that is substituted by aliphatic carboxyl or aromatic 
carboxylic acid, or 
ether that is prepared from 
hydrogen of OH that is substituted by carboxyl of 
sterol, 
monosaccharide and 
polysaccharide; R <2>, R<3> and R<4> can be H, 
alkyl containing 1 to 18 carbon atoms, perfluorinated 
alkyl containing 1 to 18 carbon atoms, -CN,-Ar, miscellaneous 
aryl, carbonyl or carboxyl 
amide. The 
coumarin compound adopts Pechmann reaction or Knovenagel reaction to introduce 
halogen atoms in the sixth and eighth positions of a 
benzene ring, to prepare the di-halogenated 7-hydroxycoumarin compound. The 
coumarin compound can be used as a fluorescent probe for marking analysis in the biotechnological research, and has the characteristics of simple operation, high stability, high sensitivity, 
high selectivity, and so on. And the 
coumarin compound is mainly used for the analysis of enzymatic activity, the 
enzyme inhibitor screening, and the detection of 
cell activity.