The HAL.31 is a new version of compost product of Tay Ninh Environment Company J.S.C, Vietnam. In this study, HAL.31 was compared the efficiency with an old version of organic fertilizer and inorganic fertilizer on the growth of Mustard greens, Water spinach, and Amaranth. The experiment was performed with six formulas, including NT1 (control – no fertilizers), NT2 (5 % product of the old process), NT3 (5 % HAL.31), NT4 (100 % inorganic fertilizer), NT5 (2.5 % HAL.31 and 50 % inorganic fertilizers), NT6 (3.75 % HAL.31 and 25 % inorganic fertilizers). The experiment was followed for 29 d and the data was collected every 7 d with two monitoring indicators such as tree height and the number of green leaves per tree. After 29 d, the heights of Mustard greens and Amaranth at NT3 were 10.58 cm and 19.58 cm, which were significantly different (p = 0.05) from the rest of the treatments. The data of Water spinach was 44.00 cm higher than those of the other treatments, but the difference was not significant with NT2, NT5, NT6 (p = 0.05). Similar results were recorded with the track of the number of green leaves per plant, the figures for Mustard greens and Amaranth were significantly different from the remaining treatments with 11.00 and 8.00. The data of Water spinach of 10.93 was higher than that of other treatments but was not significantly different compared to NT2, and NT5 (p = 0.05). The results showed that HAL.31 compost was completely suitable for the growth of three leafy vegetables in the study.