The objective of this experiment was to determine the effects of diffrente sources of starter on performance, rumen fermentation, and behavior of sucking dairy calves. Fifty two Holstein calves (BW = 41.7 ± 5 kg; mean ± SD) were randomly assigned to a completely randomized design. Experimental treatments were: 1) Control (without presence of shredded beet pulp or alfalfa hay in starter); 2) starter containing 10% of alfalfa hay; 3) starter containing 10% of shredded beet pulp; and 4) starter containing 20% of shredded beet pulp. Newborn calves after consuming a certain amount of colostrum at the age of 3 days were housed in the experimental design and were weaned at 60 days of age. Milk feeding method and levels of milk volumes were the same among treatments (5 L/d). Body weight and starter intake were recorded every 10 days during the experiment. Results showed that starter intake, average daily gain, body weight at weaning was greatest ( P 0.01) for calves consumed 10 % beet pulp. Claves consumed control starter had the greatest feed efficiency in post-weaning period ( P 0.05). The chest, abdomen, hip width, hip height and body length at the end of the experiment were highest ( P 0.05) for calves fed 10% beet pulp. Regarding behavior indeces, calves fed 10% alfalfa hay had more ( P 0.01) chewing, lying, and non-nutritional behavior than others. Dry matter, organic matter, NDF, and ADF digestibility of calves fed control diet were numerically greater, but crude protein digestibility of feed starter containing alfalfa hay was greatest ( P 0.05). Among the treatments Calves fed alfalfa hay had greater rumen pH, N- ammonia and lower VFA in pre-weaning and post-weaning than other groups. Calves were fed 10% beet pulp had the greatest concentration of acetate in rumen fluid at post weaning period and the lowest concentration of butyrate at pre-weaning period ( P 0.05). Acetate to propionate ratio was the lowest for calves fed control starter. Fecal score in both pre-weanin and post weaning periods was lower for calves consumed beet pulp than other groups ( P 0.05). Calves fed 10% beet pulp in both pre-weaning and post weaning periods had the greatest serum glucose concentration and the lowest serum BHBA (Beta hydroxy butyrice acid) concentration ( P 0.05). Calves consumed 10% alfalfa hay had the greatest blood urea nitrogen ( P 0.05). In conclusion, presence of 10% beet pulp in feed starter improved performance and health responses of sucking dairy calves. Keywords: beet pulp, starter, fiber, calves.