To uncover the eco-hydrological influence of flower and leaf litters of Rhododendron delavayi at the Baili Dujuan Natural Reserve, the litter bag method in the field and indoor soaking method were applied to study the water holding characteristic of flower-leaf mixture during their decomposition. The results were as follows: (1) The cumulative decomposition rates of R. delavayi increased with decomposition time and growing flower ratio, and the cumulative decomposition rates of each flower-leaf mixture rate varied between the pure flower and pure leaf litters; (2) The relation between water holding ratio and soaking time was a logarithmic function (R=a ln t+b, R²>0.80), the water holding ratio increased instantly within two hours, then turned to slowly within 2~8 hours and leveled off after 8 hours; while the absorption speed rates of litters decreases with soaking time in a power function as (V=ktⁿ, R²>0.99), with the highest absorption speed rate within 4 hours and levelled off thereafter; (3) The maximum water holding rate of different flower-leaf mixture litters increased with decomposition time and flower ratios, but the difference among different flower ratios was lowered with decomposition time; (4) The maximum water holding capacity of different flower-leaf mixture was regulated by the decomposition rate and water holding rate. The maximum water holding capacity of different flower-leaf mixture of R. delavayi increased with flower ratio during 0~360 days, while the flower ratio didn’t work after 450 days of decomposition. In a whole, the R. delavayi utilization should not exceed the half of the current flower litter to maintain the litter decomposition rate and improve the water holding rate.