Vitamin and mineral deficiency in dairy cattle cause a lot of damages to milk production and reproduction efficiency. Reduced fertility of dairy cattle has a lot of economic losses for cattlemen. In this study has been dedicated to consider the reproduction and metabolic result of using oral bolus containing vitamins and minerals with or without injecting hCG and GnRH hormones. For this purpose 36 dairy cattle have been selected, producing more than 11000 liters of milk and with parity in the previous 305-day-peroid, from one of the units located around Qom. The selected cattle have been randomly categorized into 4 groups, so that in each group cattle were equal in the average of parity (2.5) and milk production (11000 liters). The groups were as follows: 1- without using bolus and hormone (control), 2- using mineral-vitamin bolus, 3- injecting GnRH and hCG, 4- using mineral and vitamin bolus and injecting GnRH and hCG. 2 edible, slow-released bolus containing minerals (copper: 16379, cobalt: 234, selenium: 251, manganese: 8326, zinc: 13382, iodine: 497 milligram) and vitamins (vitamin A: 549408, vitamin D: 109881, vitamin E: 1099 international units) have been used for each cattle. 5cc and 1500 international units of GnRH (on the day of artificial insemination) and hCG( 11 days after artificial insemination) hormones have been injected intra-muscularly with the following trademarks respectively: Vetospet, Pergenil. Cattle with an average physical score of 3.5 have been dedicated to the experiment and that physical score was determined 30 or 60 days after giving birth. All the cattle in this experiment have been considered by farm veterinarian in the forth fourth week after birth from the view point of returning uterus to its initial state and probable occurrence of uterine infection and establishment of ovarian activity. Cattle’s blood samples were taken in the day of artificial insemination and 12 days after that to determine the density of progesterone. Results have shown that the density of progesterone in blood (Ng in milliliter) was more among those cattle that received hormones in the day of artificial insemination and 12 days after that (p‹0.001). Reduction of score has been more among those that received plows supplement than others (p‹0.001). Using bolus had a significant effect on cows at the time of the first stallation. Results relevant to cumulative pregnancy rate showed that using bolus caused pregnancy of more cows in the third turn of insemination. There were no differences between cows in the experiment such as opened days,conception rate, the percentage of being effected by metabolic disease in experimental treatments did not differ Key words: Oral bolus, progesterone, dairy cattle and Reproductive parameters