[en] This investigation is to study gonad dose measurement for the ₆₀Co ν-ray treatments of nasopharyngeal carcinoma with the aid of two Rando phantoms in both sexes. The energy of scattered radiation in space and in tissue was investigated by means of half-value layers with thermoluminescent dosimeters. Other related factors such as field size, SSD, orientation of primary beams were also investigated. For the non-metastases case, the gonad dose for male is 1.6 -- 2.2 rads, and that for female is 3.0 -- 4.2 rads. For the metastases case, the gonad doses for both sexes are about two times more. (author)