Investigation on cell apoptosis is an important method for antitumor drug screening at the cellular level. This paper presented a microfluidic chip in which a stable drug concentration gradient of cisplatin was generated to induce the apoptosis of Hela cells. Cell apoptosis could be monitored in real-time through fluorescence resonance energy transfer (FRET) imaging system. The results showed that the cells bubbled and shrinked in morphology when the apoptosis happened, accompanied by gradually reduction of FRET signals. The degree of apoptosis proved to be drug concentration dependent on quantitation. This method provided a new way for anticancer drug evaluation at cellular level, with obvious advantages of high throughput, low cost and automation capability.