A 2-pole tunable bandpass filter was design and fabricated using ceramic coaxial resonators and varactor diodes for UHF band. By inspection of frequency characteristics of the T-and $pi$-type inverter equivalent circuits, we can design a two-pole tunable BPF with only two varactors. The measured data of the filter show 800 MHz-900 MHz tunable center frequency range, 4.5 dB insertion loss, 0.5 dB passband ripple and at least 15 dB return loss, which agree well with the simulated results.