Ultra-small sensing technology has become an important research field because of the growth of sensor network technology. To accomplish the small form factor and low power consumption, heterogeneous integration of sensing elements and circuits has attracted attentions from different aspects. In this work, conductive polymer PEDOT:PSS based resistor-type sensors are fabricated on silicon dioxide substrate. Directly inkjet printing technique provides a low-cost, room-temperature process to cast sensing films of 500nm thickness on pre-patterned Au electrodes. The Response behavior of humidity sensor operation between 20% – 80% RH is experimental determined. In addition, the directly inkjet printing the developed sensing material on the top of CMOS fabricated circuit is also demonstrated. This work demonstrates the potential to integrate sensing device on the top of CMOS IC chip.