Microwave-assisted synthesis of organic molecules has long been facilitated in organic synthesis to build versatile molecules in medicine. However, this method is limited ascribe to the uncontrolled temperature during the reaction process. Herein, a series of imidazo [4,5f][1,10] phenanthroline derivatives ROPIP(PIP = imidazo [4,5f][1,10] phenanthroline, R = CH₂CH₃, 1; (CH₂)₂CH₃, 2; CH(CH₃)₂, 3; (CH₂)₃CH₃, 4) have been synthesized at 100°C under the irradiation of microwave. We found that the imidazo increased promptly to 100°C when irradiated by microwave, and then kept almost no change during the whole process, then was cooled to 55 °C in about 3 mins. As a result, the yields of the titled compounds increased obviously in far more less times. Moreover, the inhibitory activity of these compounds against the growth of various tumor cells, including A549 human lung cancer cells, SMMC7721 human liver cancer cells and SW620 human colon cancer cells have been investigated by using MTT assay, and the results showed that these compounds exhibited promising inhibitory activity, especially against the growth of A549 cells. The underlying mechanism, as well as their DNA-binding behavior were under further investigation.