By in situ x-ray diffraction,an isostructural phase transition between two kinds of the cubic PbCrO3perovskites at around 1.6 GPa and room temperature with a 9.8％ volume change is discovered.Recently,we have synthesized this cubic PbCrO3perovskite successfully.Here we report our high-pressure in situ electrical resistance measurements up to 4.1 GPa for this perovskite sample.At room temperature,the resistance shows special changes at 1.2 and 2.7 GPa.They may indicate the starting and ending points of this transformation.At 4.1 GPa,the negative temperature resistance coefficient is observed,which means that phase Ⅱ could be considered as a semiconductor according to our present measurement.