[Objective] Mulching effects of different organic materials on evaporation and soil moisture content were studied to identify the best material for moisture retention.[Methods] The simulated evaporation analyses were conducted with garden waste in various particle sizes (M₁:0~1 cm, M₂:1~3 cm, M₃:3~5 cm). In addition the barrel control experiments were carried out with M₂, wood chips (M₄), and bark (M₅).[Results] Garden waste in various particle sizes could reduce daily evaporation of soil moisture. After 14 days of continuous evaporation, the cumulative evaporation capacity of M₂ (1~3 cm in size), M₁ (0~1 cm), M₃ (3~5 cm) and CK (control) were 193.0, 269.5, 304.0 and 1 037.0 g, respectively, which were 81.4%, 74.0% and 70.7% lower than those of CK. The soil moisture content of different layers were increased by covering with different organic materials, except for the rainy season, which were wood chips (M₄), bark (M₅) and garden waste (M₂) from high to low. The annual change of soil moisture content under various mulching layers showed a similar bimodal trend, with a low soil moisture content in the period from April to May while a high soil moisture content in the period from June to August. The annual average of soil moisture content within the 0-40 cm soil layer of M₄, M₅, M₂ and CK were 32.9%, 30.3%, 27.4%, and 26.8%, respectively.[Conclusion] Wood chips are the best materials for moisture conservation, followed by bark and garden waste.