The invention belongs to the field of biological engineering techniques and relates to a thermophilic alkaline phosphoesterase. The invention provides an amino acid sequence of a thermophilic alkaline phosphoesterase of the invention, as well as a DNA fragment encoding the amino acid sequence. The present invention also includes methods for cloning an expression vector containing the DNA fragment or a portion thereof and for producing the recombinant enzyme. The invention also relates to a method for tagging biological macromolecules utilizing the enzyme.