Tetranychus urticae Koch is one of the most important pests of cucumber in the world. In this study, the Sublethal effects of TV isolate Beauveria bassiana (Bals.) Vuill fungus on biological parameters of T. urticae in laboratory conditions with a temperature of 25 ± 2 ° C, relative humidity of 70 ± 5 and an optical period of 16 hours Lighting and 8 hours of darkness were evaluated. The analysis of the results of daily taking notes was based on the theory of bisexual life table. The average gross reproductive rate (GRR) for LC30 and control was 15/38 and 35/89 (offspring/individual), which showed a significant decrease between control and LC30 treatments. The net reproductive rate (R0) in treated with LC20 and LC30 concentrations was 14.72 and 11.19 (offspring/individual), respectively, and for control treatment, 27.75 (offspring/individual), respectively, which showed a significant decrease between experimental treatments The mites treated by distilled water, LC20 and LC30 concentrations demonstrated adverse effect of fungus on oviposition period. The intrinsic rate of increase in population (r) when mites affected by LC30 and distilled water, respectively was 0.1688 0.1983 (day-1) which indicated a significant decrease. The finite rate of increase in population (λ) with the use of LC20 and LC30 concentrations increased to 1.1963 and 1.1839(day-1), which was significantly decreased compared to the control. The generation time (T) for LC30 concentration was 14.28 (days(, which showed a significant decrease compared to control treatment of 16.73 )days(. To conclude, the result indicated that B. bassiana strain TV has could significantly affected on some important demographic parameters of T. urticae and it seems to have good potential for controlling of this phytophagus mite.