Abstarct: Due to the warm and dry climate of Iran, water shortage and drought is one of the most common agricultural problems. Therefore, finding solutions to improve soil structure and plant resistance to drought stress is of particular importance. Organic modifiers may positively affect soil hydraulic properties, soil mechanical strength and soil structure. Biochar and crop residues improve soil physical quality by increasing specific surface area, soil porosity, and soil aggregate stability, and decreasing soil bulk density. On the other hand, given the climate situation of the country, the incidence of wet and dry cycles has increased during recent years. These cycles are amongthe factors influencing the stability of soil structure. Accordingly, with the aim of assessing the impact of biochar and wetting-drying cycles on soil available water concepts, the current research was carried out using a factorial experiment in completely randomized design, including two factors of drying and wetting cycles were performed at five levels (zero, 2, 4, 8 cycles and constantly wetting) and organic matter at three levels (biochar, plant residue and control sample). After mixing with biochar, the soil was poured in cylinders with a diameter of 4 and a height of 3 cm. Then, the drying and wetting cycles were applied for a period of two months and finally, by measuring the soil moisture characteristic curve and soil mechanical strength, the concepts of soil water supply, Non-Limiting and Least-Limiting water ranges, and integral water were calculated. The results showed that organic treatments by increasing soil organic carbon decreased the mean weight diameter of aggregate particles and reduced dispersible clay and ultimately led to improved soil physical quality. On one hand, the highest soil organic matter content was observed in 2 and 4-cycle treatments and the highest mean weightdiameter of aggregates was chieved by applying 2 cycles. Addition of biochar at the weighting rate of 2.5% reduced the soil penetration resistance compared to the control under the studied suctions. Applying crop residues and biochar increased the soil moisture content by 0.44 and 0.53, respectively, compared to the control in the initial suctions, and this increase was more evident under the suctions less than 100 cm. Overall, the greatest effect of wetting-drying cycles on increasing soil water retention was related to the treatment of two cycles. Applying wet and drying cycles increased plant available water (〖 〖PAW〗_330 و PAW〗_100) from 0.079 in the control treatment to 0.1938 in the biochar treatment. In the control treatment without residues and in the soils treated with crop residues, the increased number of wetting-drying cycles raised soil moisture contet in both limits of field capacity and permanent wilting point. Similarly, when applying biochar and plant residues, the use of dry and wet cycles has increased the moisture in least limiting water range compared to the zero non-cycle treatment. Also, the application of organic treatments in the soil increased twice the air filled porosity of 10% in the biochar treatment (0.4494) compared to the control treatment (0.2419). The results of this study showed that the addition of biochar and the application of cycles increased the aggregate reconstruction and improvement of the soil structure, consequently reduces the soil penetration resistance. The use of biochar and plant residues can be a useful solution in soil management, considering the possibility of further expansion of wet and drying cycles in the soils of the country due to climate fluctuations and changing rainfall patterns.