The present invention relates to a composition for treating chronic inflammatory pain containing a pyruvate dehydrogenase kinase (PDK) inhibitor as an active ingredient and a composition for diagnosing chronic inflammatory pain containing a formulation measuring an expression level of mRNA of a PDK gene or a PDK protein. The PDK inhibitor of the present invention reduces an inflammatory response in an animal model where chronic inflammatory pain is induced and diminishes hindpaw edema and pain behaviors. Thus, the PDK inhibitor of the present invention can be useful for treating chronic inflammatory pain. Also, the PDK inhibitor of the present invention can be used for diagnosing chronic inflammatory pain by measuring the PDK expression level, since the PDK expression increases when chronic inflammatory pain is induced.
