Abstract: A method was proposed for the determination of patulin in canned supplementary food fruit puree for infants and young children by ultra-high performance liquid chromatography tandem mass spectrometry with solid phase extraction. The sample was hydrolyzed by pectinase, extracted by ethyl acetate, purified by MAX solid phase extraction column. The separation was performed on Waters BEH C₁₈ column, then the detection was performed in the electrospray ion source negative ion and multiple reaction monitoring modes. The isotope internal standard method was used for quantification. As shown by the results, linear range of standard curve for patulin was 10.0-200 μg·L^-1, with detection limit (3S/N) of 2 μg·kg^-1. Test for recovery was made by standard addition method, giving results in the range of 101%-112%, with RSDs (n=6) of the determined values less than 4.0%. This method was applied to determination of patulin in 33 commercially available canned supplementary food fruit puree samples, and patulin was not detected.