In this study, we particularly aimed to research the effect of supplemental humic acid on ruminal fermentation and blood variables in rams. A trial was conducted to evaluate the effect of humic acid (HA) on protozoa count, percentages of different protozoa types and blood parameters. Three male Kivircik rams with ruminal cannula were used in a Latin square design, during 22 days periods (15 days for adaptation, 7 days for collection). They received 0 control group (CG), 5 g/day or 10 g/day of HA (HA5, HA10, assay groups). HA were added to the ration with grain diet. Ration was consisted of 5% grain diet and 95% alfalfa hay. Rumen contents collected before and, 3h and 6h after morning feeding on days 1 and 7 in each collection period were analyzed. Blood samples were also collected the same days. No significant difference in biochemical and hematological parameters (except eosinophils levels, P<0.05), variables of ruminal fluid (except sodium levels before feeding) and species of rumen protozoa organism (except the percentage Epidinium spp.) were evidenced with the addition of HA. In conclusion, we think that they might have been true the widely use in animal food of humates which don't have any negative effect on biochemical and hematological parameters in particular.