A content preference degree calculating method and system that calculates preference degrees of viewers to contents such as broadcast programs in conformity with the actual viewing pattern. In a preference degree calculating unit, the value of a function which is based on at least the rate Ru (=Dw/Lu) of a viewing time (Dw) of the content concerned to a unit time (Lu) and the rate Rc (=Dw/Lc) of the viewing time (Dw) of the content concerned to the time length (Lc) of the content concerned. When the preference degree (Pr) increases as the rate (Ru) is increased and the preference degree (Pr) increases as the rate (Rc) is increased is calculated as a preference degree (Pr) of a viewer to the program concerned from program viewing record data. A formula is Pr=Ru+Rc=(Dw/Lu)+(Dw/Lc). In a preference degree renewing unit, the preference degree (Pr) is added to a pre-renewal preference degree (Po) recorded in a preference data base by some rate, and the preference degree (Pn) after the addition is recorded as a post-renewal preference degree into the preference data base.