As a model of polymer-sustained-alignment liquid crystal display (PSA-LCD), the LC cells having the PSA layers formed from mixed monomers of 2,7-dimethacryloyl-oxy-phenanthrene (2,7-DMAPhen) and 4,4 '-dimethacryloyl-oxy-benzilketal (4,4 '-DMABzk) were fabricated and investigated image sticking phenomenon with evaluations of residual direct current voltage (V (rDC)) and difference in pretilt angle (Delta tilt) before and after application of alternate current voltage. A rate constant of the polymerization became large with an addition of a small amount of 4,4 '-DMABzk into 2,7-DMAPhen. The V (rDC) was effectively improved with the addition of a small amount of 4,4 '-DMABzk because the concentrations of radical and/or ion in the LC layer were decreased due to enlargement of the rate constant of the polymerization. The Delta tilt was small enough only below 9.1 wt% of 4,4 '-DMABzk in the mixed monomers of 2,7-DMAPhen and 4,4 '-DMABzk. We confirmed that the PSA-LC cell formed from the mixed monomers of 2,7-DMAPhen and 4,4 '-DMABzk with the weight ratio of 4,4 '-DMABzk between 3.8 wt% and 9.1 wt% was useful for obtaining the low level of image sticking.