Lettuce (Lactuca sativa L.) and Japanese bunching onion (Allium fastulosum L.) roots were soaked in L-ascorbic acid solutions (1500 mg L^-1) of various pH values for 12 h and changes in leaf ascorbic acid contents (the total content of L-ascorbic acid and dehydroascorbic acid) were analized. The ascorbic acid content in the leaves increased with a decrease in the pH value of the treatment solutions. In the treatment of the lowest pH value (pH 3.1), the ascorbic acid content in the lettuce leaves was increased from the initial value of 26±8 mg (per 100 g of fresh weight—the same will apply hereinafter) to 191±21 mg, while that in the bunching onion leaves was increased from the initial value of 34±8 mg to 183±17 mg. In the case of lettuce, the water absorbing ability of the roots worsened as the plants growth proceeded and thus the increased rate of the ascorbic acid content in the leaves was lowered simultaneously. These results suggest that lettuce and bunching onion absorb ascorbic acid well when the treatment solution has a pH value of 3.1. It also indicates that lettuce accumulates ascorbic acid in the leaf at a high level when young plants are treated.