To develop a convenient and sensitive point-of-care test for detecting gene mutations based on allele-specific PCR. To develop a lateral flow strip for visual detection of K-ras mutations based on a modified PCR, a specific DNA tag was covalently linked to the 5'-end of each primer by a nine-carbon linker to produce a sticky end. One of the sticky ends of the PCR products bound to gold nano-particles, while the other sticky end was captured onto a nitrocellulose membrane of lateral flow strips. The lateral flow strip showed a great sensitivity, which detected mutations in as low as 10 tumor cells. The positive rate and accuracy of the lateral flow strip for blood samples were over 92 and 96 %, respectively. The lateral flow strip provides an easy method for sensitive detection of gene mutations based on allele specific-PCR.