Here, we report the generation of optical imaging reporter breast tumor cells that allow the longitudinal, in vivo, noninvasive imaging of gene recombination in tumor. Tumor-gene targeting is a promising approach of treating cancers, and a suitable gene delivery method is the criteria for success. By using the cre lox genetic engineering tool, we targeted stable green fluorescent protein expression in metastatic-prone human breast cancer MDA-MB231 cells that switch to express firefly luciferase upon the exogenous delivery and expression of cre DNA recombinase. We tested this model in vivo by intratumor injection of cre adenovirus and demonstrated the usefulness of this model to achieve longitudinal bioluminescence imaging of DNA recombination in tumor. This optical imaging vector and tumor model will facilitate the research for biomaterial solutions for carriers in gene therapy, and in studies on tumor targeting, tracking for tumor metastasis and migration of tumor stem cells, and for determining the anticancer drug efficacy.