Cucumber is one of important crops and susceptible to root disease caused by Rhizoctonia solani. The study aimed to evaluate the efficiency of two isolates of P. ostreatus (Ah and Ak) and soil treatment with several rates of Typha domingensis residues fermented by P. ostreatus to control R. solani that causes root diseases on cucumbers. In vitro trails, R. solani inhibited significantly by isolate (Ah) as well as redial mycelial growth and the percentage of cucumber seeds germination. In field trails, the number of germinated seedlings was highest at fermented T. domingensis 59.81 compare to control treatment which was 59.81. Disease severity (DS) of root damage was recorded in R. solani and R. solani + Fermented T. domingensis treatments and reached 70.4 and 64.27 respectively.