Abstract: This paper reports a method: simultaneous determination of fluorouracilum and ethylparaben in polyphase liposome using moving window averaging smoothing Kalman filtering spectrophotometry. After the data being smoothed, the Kalman filtered results were found to be more accurate. The method was successfully used in the simultaneous determination of multicomponent in complex base material. Test with artificially mixed sample showed that the estimates over a wavelength range 269～273 nm were more accurate. The results of artificial sample showed that the percent of recoveries for fluorouracilum and ethylparaben were 99.3～102.6 and 97.8～103.0, respectively; when there was systematic error, the percent of recoveries were 99.4～102.7 and 97.0～102.9, respectively.