Abstract: A HPLC method was developed for the simultaneous determination of euscaphic acid, 2α,19α-dihydroxy-3-oxo-urs-12-en-28-oic acid, maslinic acid, corosolic acid, oleanic acid, and ursolic acid in Malus doumeri fruits. Analyses were conducted on the distribution and content of these six triterpenic acids in Malus doumeri fruits from six producing areas in Guangxi. Using gradient elution at a flow rate of 0.8 mL/min, a Diamonsil C₁₈ (2) column was used with a mobile phase of 0.1% formic acid aqueous solution/methanol (v/v). The detection wavelength was 210 nm and the column temperature was 30 ℃. The results showed that the mass concentrations of the six triterpenic acids had a good linear relationship with the chromatographic peak areas in the linear range. The correlation coefficients were greater than 0.9990, the detection limits were within 0.46~2.00 μg/mL, the lower quantitation limits were within 1.53~6.67 μg/mL, the coefficients of variation were less than 5.0%, and the recovery percentages were within 99.2%~101.3%. Six samples from different production areas contained six triterpenic acids (euscaphic acid, 2α,19α-dihydroxy-3-oxo-urs-12-en-28-oic acid, maslinic acid, corosolic acid, oleanic acid, and ursolic acid). Each of the six triterpenic acids was a pentacyclic triterpenic acid. Among the six triterpenic acids, euscaphic acid and 2α,19α-dihydroxy-3-oxo-urs-12-en-28-oic acid were first detected in Malus doumeri fruits. Ursolic acid, euscaphic acid, and 2α,19α-dihydroxy-3-oxo-urs-12-en-28-oic acid were predominant, accounting for 71.82%~81.38% of the total triterpenic acids. The total triterpenic acids content ranged from 808.74 to 1090.75 μg/g FM. The total triterpenic acids content of fruits from Liujiang district of Liuzhou and Pingle of Guilin were relatively high, reaching 1090.75 μg/g FM and 1045.20 μg/g FM, respectively. Overall, this study's HPLC method can detect the triterpenic acids content of Malus doumeri fruits and provide scientific references for the quality evaluation of Malus doumeri fruit's raw materials and products.