Abstract: ObjectiveEffects of foliage spraying earthworm amino acid liquid fertilizer on cucumber quality were ana-lyzed in order to provide reference for application of earthworm amino acid liquid fertilizer in vegetable planting. MethodH1(foliage spraying 0.3% KH2PO4), H2(foliage spraying earthworm amino acid liquid fertilizer 800 times dilution+0.3%KH2PO4),H3(foliage spraying earthworm amino acid liquid fertilizer 500 times dilution+0.3% KH 2PO4),H4 (foliage spraying earthworm amino acid liquid fertilizer 300 times dilution+0.3% KH2PO4 ) ,H5 (foliage spraying earthworm amino acid liquid fertilizer 800 times dilution),H6(foliage spraying earthworm amino acid liquid fertilizer 500 times dilu-tion),H7(foliage spraying earthworm amino acid liquid fertilizer 300 times dilution), and control with clear water(CK) were set. Cucumber seedlings at fruiting period were treated by the eight treatments. Vitamin C (Vc), protein, soluble re-ducing sugar, organic acid, nitrate contents and sugar-acid ratio of cucumbers were detected after harvest. ResultCompared with CK,H2,H3 and H4 significantly increased Vc content in cucumber by 40.0%, 53.5% and 38.0%(P<0.05, the same below),H2, H3, H4, H6 and H7 significantly decreased nitrate content by 55.2%,85.3%, 67.5%, 31.6% and 49.6% respectively. H3 significantly increased protein content by 31.2%. Soluble reducing sugar content significantly declined in all fertilization treatments, and those in H4, H5 and H6 were significantly lower than that in CK. H2 and H3 significantly reduced organic acid content by 14.2% and 22.8% , and H5, H6 and H7 significantly decreased organic acid content by 39.1%, 44.8% and 36.8%. Compared with H5, H6 and H7 respectively, H2, H3 and H4 increased Vc content,lowered sugar-acid ratio, and organic acid contents were significantly higher, significantly reduced nitrate contents were significantly decreased by 60.8%,78.5% and 35.5% respectively. Soluble reducing sugar contents in H2 and H3 were sig-nificantly increased. ConclusionSpraying earthworm amino acid liquid fertilizer with proper concentration on cucumber during fruiting period can improve the overall cucumber quality, and earthworm amino acid liquid fertilizer 500 times dilu-tion+0.3% KH2PO4 has the optimal effects.