This paper studied the effect of propiconazole on plant height and yield of flowering Chinese
cabbage and its residue dynamic state in flowering Chinese cabbage in autumn at Guangzhou region by field
experiment through spraying propiconazole with high dosage（375 g·hm^-2 of active ingredient）and low dosage
（250 g·hm^-2 of active ingredient），respectively 27 days after sowing．The result indicated that 7 days after
spray，the plant height treated wit high and low dosage decreased significantly by 16.7% and 18.8%，respectively
than that of the contrast the yield of flowering Chinese cabbage sprayed with low dosage was significantly less than
that of the contrast．While，there was no obvious difference between the flowering Chinese cabbage sprayed with
high dosage and the contrast．Ten days after spray，the plant height treated with high and low dosage decreased
significantly by 18.0% and 17.5% than that of the contrast，respectively．While，there were no significant
differences in their yields with the contrast．Dissipation dynamics of propiconazole in flowering Chinese cabbage
was fitted to the first kinetics equation with 1.7 days half-life．Three to seven days after spray，the terminal
residues of propiconazole were 0.210-2.207 mg·kg^-1 and dietary exposure risk quotients were within the
acceptable range of 1.73%-18.16%．Dietary exposure risk quotients of propiconazole for 408 flowering Chinese
cabbage samples from trade market in Guangzhou were 0.09%-0.58%，which was also within the acceptable
range．The detection rate of propiconazole was 50.5%-90.5%．The detection rate，average and maximum
detection values of the positive sample in the 2nd and 3rd quarters of 2016 were apparently higher than those in
the 4th quarter of 2016 and first quarter of 2017.