Polyimide (Pi)/Polyacrylonitrile (PAN) polyblend films were prepared using solution cast technique by spin coating unit. PAN was incorporated within the PI matrix in different concentration i.e. 10(-3), 10(-2), 10(-1), and 1 wt% to prepare polybiend films. The PI polybiend film incorporated with 10-1 wt% PAN and cured at 330 degrees C produces well defined quasi carbon whiskers within the PI matrix. Evidence of the orientation of these carbon whiskers was indicated by optical microscopy and AFM. The improved microhardness, mechanical performance, and hydraulic resistivity of 10(-1) wt% PI/PAN polybiend film was observed and attributed to the orientation of these partially carbonized whiskers within PI matrix. The overall property decreases with increasing the concentration of PAN over 10(-1) wt%. The incorporation of ultra low concentration of PAN within the PI provides means of achieving excellent combination of microhardness, mechanical, and hydraulic resistance with improved morphology.