High production cows at the beginning of the parturition due to high milk production and a negative energy balance are facing a lot of metabolic problems, so the aim of this study was to evaluate the effect of shortening dry period and body condition score (BCS) on colostrum quality, blood metabolites and some reproductive parameters in high-producing dairy cows. For this purpose, 120 multiparous Holstein dairy cows were allocated in two groups of 60 cows with a usual dry period (about 50 days) and a short dry period (about 28 days). Then, each group was divided into two sub-groups of 30 cows with a body scores of moderate (3) and high ( 3.5). All cows were fed in group with the similar diets. Cows fed total mixed rations (TMR) formulated according to the NRC (2001). In order to determine BCS the thickness of subcutaneous fat layer between the pin and the hip was measured by ultrasonoghraghy in early dry period, 0, 28 and 56 d postpartum. Colostrum sample of each cow was taken from the first-milking postpartum and the colostrum volume was recorded. Blood samples were collected from coccygeal vein on 0, 14, 28 and 56 d postpartum in 10 cows randomely selected from each group. In order to determine the reproductive parameters in experimental cows, firstly their estrus cycle synchronized using the Presynch-Ovsynch protocol from day 35 postpartum. Then, at days 58 and 16 h after last injection artificial insemination was done. The results showed that short dry period decreased the difference between BCS on day 28 postpartum and parturition (P 0.01), the difference between BCS on day 56 postpartum and early dry period (P 0.01), and difference between BCS at parturition and day 56 postpartum (P 0.001). Short dry period decreased (P 0.02) colostrum volume, and highest (P 0.001) colostrum volume was obtained in group of long dry period and high BCS. Decrease in length of dry period increased (P 0.02) serum insulin concentration on day 14 of lactation. In addition insulin level was higher (P 0.04) in group with short dry period and moderate BCS compared to group with usual dry period and moderate BCS. On day 28 of lactation, concentration of glucose was higher (P 0.03) in group with short dry period and moderate BCS than the group with usual dry period and moderate BCS. The NEFA concentration was higher in cows with usual dry period than cows with a short dry period on days 28 (P 0.006), 56 (P 0.03) and total period (P 0.04). The concentration of BHBA was higher in cows with usual dry period than cows with short dry period on day 14 (P 0.01) and total period (P 0.02). Short dry period decreased open days (P 0.001), days to first postpartum estrus (P 0.003), and the services per conception (P 0.004). The cows with a short dry period and moderate BCS had lower open days (P 0.001), days to first postpartum estrus (P 0.001), and the services per conception (P 0.002). Morover, decreasing the length of dry period increase (P 0.04) pergnancy rate after first service and greater (P 0.008) percentage of cows got cleaned test on day 30. Cows which had highest (P 0.001) pregnancy rate after first service and cleaned uterus up to 30 day postpartum, belong to the group with short dry period and moderate BCS. In general, results of this study showed that shortning dry period and moderate BCS could improve the energy balance condition and also reproductive performance in high-producing dairy cows. Keywords : Dry period, Body condition score, Blood metabolites, Reproduction, Colestrum, Dairy cows