Abstract: ObjectiveTo investigate contents of plant growth regulator (PGR) residues in bean sprout sold in market in a city and to estimate the health risk of dietary PGR intake from bean sprout.MethodsUsing simple random sampling method, samples of soybean sprouts and mungbean sprouts were collected from farmers markets and supermarkets. Contents of 4-Chlorophenoxyaceticacid, 2,4-Dichlorophenoxyacetic acid, Naphthaleneacetic acid，Gibberellin，and indolebutyric acid in the samples were determined by high-performance liquid chromatography tandem mass spectrometry. The exposure risk to residents caused by the PGR s in bean sprouts was evaluated. ResultsA total of 78 samples were collected from farmers markets and supermarkets in the city, including 45 samples of soybean sprouts and 33 samples of mungbean sprouts. The average contents of 4-Chlorophenoxyaceticacid and 2,4-Dichlorophenoxyacetic acid were 0.097 and 0.004 mg/kg in the soybean sprouts, respectively. The average content of 4-Chlorophenoxyaceticacid was 0.026 mg/kg in the mung sprouts. The average exposure level of 4-Chlorophenoxyaceticacid and 2,4-Dichlorophenoxyacetic acid in soybean sprout were 6.2×10-5 and 2.5×10-6 mg/ (kg bw?d), accounting for 1.03% and 0.02% of the health guidance values. The high dietary exposure level of 4-Chlorophenoxyaceticacid and 2,4-Dichlorophenoxyacetic acid in soybean sprout were 2.0×10-4 and 8.3×10-6 mg/ (kg bw?d), accounting for 3.33% and 0.08% of the health guidance values, respectively. The average dietary exposure level and high dietary exposure level of 4-Chlorophenoxyaceticacid in mung sprout were 1.6×10-5 and 3.6×10-5 mg/ (kg bw?d), accounting for 0.27% and 0.60% of the health guidance values, respectively. Naphthaleneacetic acid，Gibberellin，and indolebutyric acid were not detectable in the sprout samples.ConclusionPGRs 4-Chlorophenoxyaceticacid and 2,4-Dichlorophenoxyacetic acid could be detected in bean sprouts purchased in the markets in a city. The dietary exposure levels in the city residents are far below the health guidance values, indicating that dietary exposure to the five PGRs in bean sprout could not pose a health risk to the residents.