Abstarct: The use of biological fertilizers especially plant growth promoting bacteria instead of chemical fertilizers is the most important nutritional strategy in the sustainable management of agricultural ecosystems. A field experiment as randomized complete block design with three replications was conducted to study the effect of biological fertilizers and application of metribuzin herbicide on tomato chlorophyll content and relative water content, in research farm of University of Shahrood in 2013. The experimental treatments included T1: weeding all season, T2: no weeding all season, T3: inoculated with Pseudomonas fluorescens T4: inoculated with Azotobacter crococum T5: Metribuzin (500 g per ha from commercial type), T6: Metribuzin (1000 g per ha), T7: Metribuzin (1500 g per ha), T8: Metribuzin (500 g per ha)+ P. fluorescens, T9: Metribuzin (1000 g per ha) + P. fluorescens, T10: Metribuzin (1500 g per ha) + P. fluorescens, T11: Metribuzin (500 g per ha) + A. crococum, T12: Metribuzin (1000 g per ha) ) + A. crococum, T13: Metribuzin (1500 g per ha) + A. crococum. In addition to measuring the growth and functional traits in tomato, the population of soil bacteria in the different treatments was calculated. The results showed that the use Metribuzin (500 g per ha) + A. crococum and Metribuzin (500 g per ha)+ P. fluorescens treatment resulted in an increase in 89.57 and 63.52 percent of bacteria compared to control weeds (without control) respectively. These treatments also resulted in increasing order 97.4 and 82.19 percent plant height, 55.23 and 66.16 percent of the total number of fruit, ripe fruit than 15.33 and 84.36 percent were weedy. The results showed that the amount RWC for the treatment of P. fluorescens was compared to no weeds to the 73.44 percent. Herbicide treatments, especially yards Metribuzin 1500 grams heavy and significantly reduced the number and dry weight of weeds were at the same level. The results showed that the use of herbicides and herbicide Metribuzin (500 g per ha) + A. crococum and Metribuzin (500 g per ha)+ P. fluorescens 25.29 and 69.33, respectively, reduced the percentage of the dry weight of weeds and weed 25.29 and 62.33 per cent compared to the control. The treatment of Metribuzin (500 g per ha) + A. crococum and Metribuzin (500 g per ha)+ P. fluorescens 87.43 and 45.47 percent alone in order to reduce the 86.47 and 86.43 percent of the dry weight of weeds and weed were compared to weedy. baxsed on the results of this trial application of bio-fertilizers A. crococum and P. fluorescens alone or together with 500 g ha Metribuzin yards herbicide can enhance the growth and yield of tomatoes and reduce the number and dry weight of weeds