An rf-SQUID has been fabricated on Hg 0 . 8 Tl 0 . 2 Ba 2 Ca 2 Cu 3 O 8 + δ thin film using natural grain boundary weak links. The film was prepared by the spray pyrolysis technique and had T c = 123 K. Voltage-flux modulation of the SQUID has been observed up to 117.5 K. The flux noise density, √S φ of the rf-SQUID is 2.5 10 - 3 Φ 0 /√Hz at 1 Hz and 77 K. The value of √S φ remains almost the same when the operating temperature is increased from 77 to 112 K, and its value becomes 4 10 - 3 Φ 0 /√Hz at 114 K.