In this paper

an insulated

watercooled microwave dipole applicator radiating in a biological tissue

is analyzed with a theoretical electromagnetic mode. The specific absorption rate （SAR）distribution is calculation is calculated taking into account the effect of the water flowing inside the applicator

and compaed with the SAR distribution of no-water-cooled radiating dipole. The result suggests that

the SAR distribution will be improved on the extension of the therapy depth due to the effect of water-cooled

and it comforms to the engineering experiments and clinical reality.