Abstract: It was found that plumbum (Ⅱ) could quench the fluorescent intensity of ofloxacin in acid medium.Thus, a fluorescent spectral method for the determination of trace plumbum (II) was developed. Under the optimal experiment conditions, the fluorescent quenching intensity responded linearly with plumbum ( Ⅱ) concentration in the range of 3.0×10-7¹.0×10-5mol·L-1. And a detection limit of 8.4×10-8mol·L-1was estimated.The relative standard deviation (RSD) of this approach response to 1.0×10-6mol·L-1plumbum (Ⅱ) was 3.2% for11 successive measurements. This proposed method had been applied to detect the content of plumbum (Ⅱ) in three kinds of vegetable samples and the recovery was between 94.46% and 101.5%.