In this paper， the RF power performance and surface temperature distributions for a multi-finger power hetero-junction bipolar transistor （HBT） with non-uniform emitter finger spacing （NUEFS） without the use of emitter-ballasting-resistor （EBR） are measured， and are compared with a multi-finger power HBT with EBR. The experiment results show that for the multi-finger power HBT with NUEFS， the highest surface temperature is lowered， the uniformity of surface temperature distributions measured by US QFI Infrared TMS is improved， the RF power gain and power-added-efficiency （PAE） are increased compared with the multi-finger power HBT with EBR respectively. These results could be attributed to the improvement in positive thermoelectric feedback and thermal coupling effects among the fingers， and the riddance of adverse impact from emitter-ballasting-resistor used in traditional power HBT.