Objective: To screen aptamers to carcinoembryonic antigen (Anti-CEA), which will lay the experimental foundation for obtaining aptamers to serum tumor markers of lung cancer. Methods: We used carboxyl magnetic microspheres (CMM) as carrier, anti-CEA for the screening target, and subtractive SELEX as well as real-time quantitative PCR techniques to screen aptamers to anti-CEA from random single-stranded oligonucleotide libraries. We identified the anti-CEA-aptamers via electrophoretic mobility shift assay (EMSA). And then, the 10th round of screening was amplified for double-stranded DNA, purified by gel after cutting, connected with PMDTM18-T vector and transformed in the competent cell of Ecoli.DH5α. Meanwhile, we identified positive clones through interlaced PCR technique. Finally, we obtained sequences of aptamers. Results: The results showed that four aptamers connected with Anti-CEA were obtained with different sequences after 10 rounds of screening. Conclusion: The specificity test of screened binding apatamers demonstrated that with No.2 aptamer has a high specificity to Anti-CEA, and it could not be bound with non-specific proteins. These aptamers could be used to recognize the Anti-CEA, ultimately, to offer a new breakthrough for the early diagnosis and early treatment of lung cancer.