Abstract: 【Objective】The objective of the paper was to study the interaction between 5 kinds of furancoumarin molecules and DNA and analyze their potential risks. 【Methods】The DNA binding saturation value (DNA BSV) of furanocoumarin molecules binding with DNA was calculated through resonance light scattering (RLS), and the drug molecules’ability to bind with DNA was reflected by such BSV to evaluate their potential risks.【Resultsv】 The results of recovery experiments indicated that these furocoumarin molecules could enter or partially enter Escherichia coli cells and interact with DNA. The changes of RLS signals of furan-coumarin molecules were similar to those of ethidium bromide; the capacity of furan-coumarin molecules that enter E. coli DNA was ranking as follows: iopsoralen/psoralen ＞ xanthotoxol ＞ bergapten ＞ xanthotoxin.【Conclusion】Furancoumarin molecules could be transferred from external of E. coli to its internal and interact with their DNA, and the binding pattern may be insertion. It was speculated that the 5 tested furancoumarin molecules showed little potential risks but there was still some by calculating the respective DNA BSV.