Recent statistics show that the incidence and mortality of cancer are on the rise. Among all types of cancer, lung cancer and liver cancer are the most prevalent. We have many biomarkers for these two cancers, among which the cytokeratin fragment 21-1 (CYFRA 21-1) and α-fetoprotein (AFP) are the most common and widely used. Among the various detection methods, the field effect transistor (FET) biosensor is one of the most attractive approaches, providing a label-free, fast, and low-cost electrical detection of biomarkers with high specificity and sensitivity. In previous work, we applied biomarkers for a single cancer type. With the detection of CYFRA 21-1 and neuron-specific enolase (NSE), lung cancer was differentiated in the early stages. Compared with the early work, the biomarkers for the two cancer types, CYFRA 21-1 for lung cancer and AFP for liver cancer, were prepared in this work. The detection of CYFRA 21-1 and AFP in human serum was achieved at the same time with the limits of detection of 1 and 0 ng mL-1, while the cut-off values were 4 and 10 ng mL-1. The method featured short analytical time, small sample volume, and low cost. With its good selectivity and appr priate sensitivity, clinical application will become popular in the future.