This study was conducted to determine the quantity of acidic cannabinoids converted to neutral cannabinoids during the 15-day storage period. The secretory cavity contents acquired from the capitate-stalked glandular trichomes by glass microcapillaries and air-dried inflorescence were analysed by high-pressure liquid chromatography. The ratio of acidic cannabinoids to the total cannabinoids was much lower in the air-dried inflorescence samples compared to the secretory cavity samples as follows. In the secretory cavity content, the percentage of acidic cannabinoids to the total cannabinoids was measured as 86.7% cannabidiolic acid (CBDA), 1.4% cannabigerolic acid (CBGA), 4.1% cannabichromenic acid (CBCA), and 6.4% Δ 9-tetrahydrocannabinolic acid (Δ 9-THCA), respectively. In the air-dried inflorescence, however, the acidic cannabinoids were detected with 42.5% CBDA, 0.4% CBGA, 1.7% CBCA, and 2.4% Δ 9-THCA, respectively. The ratio of cannabidiol (CBD) to cannabidiolic acid (CBDA) was close to 1:95 (w/w) in secretory cavity contents, however, it was roughly 1:20 (w/w) in the air-dried inflorescence. In addition, Δ 9-tetrahydrocannabivarin (Δ 9-THCV) and Δ 9-tetrahydrocannabivarinic acid (Δ 9-THCVA) were only detected in the air-dried inflorescence sample, and the ratio of Δ 9-THCV to Δ 9-THCVA was about 1:20 (w/w). Besides, cannabidivarinic acid (CBDVA) was only observed in the secretory cavity content.