A noval method was established for the detection of four alternaria mycotoxins,iealternariol,alternariol monomethyl ether,tenuazonic acid and tentoxin in jujube by ultrahigh performance liquid chromatography-tandem mass spectrometry.The sample was extracted with 2.0% formic acid-acetonitrile by sonication and auxiliarily salted out with 0.2 g NaCl.Four alternaria mycotoxins in jujube were separated on a BEH C18 column in 6 min,and dectected in multiple reaction monitoring mode(MRM).The calibration curves for 4 alternaria mycotoxins showed good linearities in the ranges of 1.0-100 μg/L for alternariol and 10-1 000 μg/L for the other three toxins,with their correlation coefficients larger than 0.990 and the detection limits of 0.5-12.4 μg/kg.The spiked recoveries for 4 toxins in blank matrix were between 92.8% and 116% with the relative standard deviations of 0.5%-11.2%,which could meet the requirements for detection of alternaria mycotoxin in jujube.Moreover,the permitted daily exposures(PDE) for adults against 4 types of toxins were obtained to be 19.30-25.65 μg/d based on the calculation of the toxicological software theory.