Application of organic materials is a common practice to increase soil aggregates and its stability, but the use of sugarcane pulp extract as a soil structural improvement, expressed in terms of mean weight diameter (MWD), has not been tested so far. Therefore, a laboratory experiment was conducted on intact soil core samples in a randomized complete design with two factors, i.e., two sources of extract (1) fresh sugarcane pulp (FSP) and (2) compost of sugarcane pulp (CSP), and seven drying and wetting cycles, plus the control (tap water only). Each soil core received an extracted volume of 175 cm3 (equivalent to the addition of 10 t FSP or CSP ha-1) on parts 25 cm3 for each cycle. The effectiveness of CSP extract was 3-folds as that of FSP extract in improving MWD. The most pronounced effect was at the 4th cycle, suggesting that 100 cm3 of CSP extract (equivalent to the addition of 6 t CSP ha-1) instead of 175 cm3 appears to be sufficient for improving the soil structural stability. Overall, the extract derived from CSP could be a faster way in improving soil structure than FSP which takes time to decompose and shows its benefits. However, more future investigations should be expanded to other types of soil and field trials to obtain further information to be used in advising land managers, especially those who use a drip-irrigation system.