The transition from the vegetative phase to reproductive phase is the most important event in production and genetic innovation. This phenomenon is influenced by many genetic and environmental factors in plants. According to studies carried out in this field, one of the environmental factors affects the reproductive and flowering process is Trichoderma species, which is abundant in soil. This study was carried out to evaluate the ability of two recombinant Trichoderma harzianum strains containing chimeric chit 42 (with CHBD domain) and wild -type strain to promote common bean flowering and yield increase in vivo condition. To do this, flowering parameters such as a number of flowers, flowering time and effective parameters in yield were evaluated. Also, expression level of some flowering -related genes such as FT and SOC1 were measured using real -time PCR. The results showed that the bean plants treated with recombinant strains had a significantly increased number of flowers and earlier flowering compared to the control and wild type Trichoderma. Also, plants treated with recombinant strains showed a significant difference in the number and weight of the pod compare d to the plant treated with wild type strain and non -treated plants. In addition, the plants treated with T13 strain showed more expression levels of the FT and SOC1 genes (with ratio of 3.42 and 3.41 fold respectively) compared to other treatments and control plant. Finally, T13 recombinant strain exhibited a better performance compared to the other strains through a positive effect on flowering and then increase d the crop yield.