A new dual rectangular photomultiplier tube has been developed for the positron CT. It has two independent segments in a single 24mm square glass envelope. The coincidence time resolution with BG0 scintillators equal to 2.9ns in FWHM and 6.2ns in FWTM was obtained for 511 KeV positron annihilation ,γ-rays. The experimental results promise the possibility of a new PCT system design-ing of a high packing ratio and spatial resolution with good optical coupling to small rectangular BGO scintillators.