The Present study was carried out to find out the compatible dose of the fungicide with Trichoderma harzianum (TH) and the study also found way to utilize the synergy of the fungicide (Copper Hydroxide) and the fungal biocontrol agent against soil borne plant pathogen causing Fusarium wilt in Mung bean (Vigna Radiata L.). TH is a well known fungicidal biocontrol agent. The efficiency TH strain was studied against a soil borne plant pathogen Fusarium oxysporum (FO). The biocontrol strain TH was mainly observed under in-vitro assays was found to be compatible with the Copper Hydroxide, an agro-fungicide formulation sold with a trade name Kocide (KD); TH tolerated to the fungicide KD as the mycelia reduced 50% growth (EC50) at 176.1 ppm. KD increased the mycocidal potential of the TH at the highest tolerable dose (20 ppm < EC10 =58.2 ppm), from 24 to 26% against FO on food poisoned media, which was the evidence to the fungicide synergy (02%) with the biocontrol effects of the Under in vivo conditions, the synergy between KD and TH was found to be higher (26.1 %) in combating FO infection in mungbean plants in comparison to in vitro assay. Under in vivo conditions, the synergy between KD and TH was found to be higher (26.1 %) in combating FO infection in mungbean plants in comparison to in vitro assay. The combine use of KD and TH also positively impacted the plant growth where plants treated with both KD and TH had XX time dry weight (2.66 g) compared to single applications of TH (0.8 g) and KD (0.68 g). "The formulations, containing TH spore and the fungicide @ 20 ppm, would be integrated with crop managements”.