Photothermal ablation therapy (PTA) has been widely reported; however, it is not possible to predict the internal temperature of the tumor in real time that causes ineffective treatment and normal tissue burns. Here, we have designed a photothermal therapy strategy under real-time temperature
monitoring by injecting gold nanorods (AuNRs) and NaYF4: Yb3+ /Er3+ into the tumor site where AuNRs are used for PTA of cancer cells by converting the absorbed energy into heat and using Yb3+ , Er3+-NaYF 4 phosphors to monitor
the temperature inside the tumor. Our experiments confirm the effectiveness of this strategy, which is expected to be an aid in the development of real-time temperature monitoring and effective photothermal therapy for the treatment of cancers.