The $SnO_2/TiO_2$ thick film type humidity sensing devices containing 5 to 50 wt% $TiO_2$ have been fabricated by a typical screen printing technique. The surface crystal structure and microstructure were investigated by XRD, SEM and FTIR analyses. And the measurement of sensing characteristics of the thick film devices have been carried out. The crystalline phase of the thick flus were mainly identified as $(SnO_2){cdot}6T$ crystal structure with XRD analysis, and the thick films sintered at $1300^{circ}C$ showed an average particle size of $2.0{mu}m$. The $SnO_2/TiO_2$ device sintered at $1300^{circ}C$ containing 10 wt% $TiO_2$ showed high sensitivity to humidity in the range of R.H. 20-90%.