The aim of the present study was to evaluate the serum concentration of total sialic acid and adenosine deaminase activity and its effect on the severity of the disease in cattle naturally infected by Babesia. A total of 50 female cattle (40 female diseased cattle and used as a group 1, and 10 healthy female control cattle (Clinically and laboratory healthy) were used as a group 2. Babesia infection was confirmed with Giemsa staining blood film. Infected animal were grouped into mild, moderate and sever cases according to examination the degree of parasitemia. Compared to the control animals (57.6±22.88 mg/dl and 11.07±44.35µ/l) of total sialic acid, and adenosine deaminase enzyme activity, respectively. There was marked increase in mean total sialic acid and adenosine deaminse were detected.  (102.09±3.93 mg/dl and 65.18±16.30µ/l), respectively. This marked increase without related to the severity of the disease. In diseased ones correlating was not with sialic acid and adenosine deaminase enzyme (r=0.027p>0.05). It can be concluded that Babesia infection in cattle induced marked increase in the serum level of sialic acid concentration and adenosine deaminase enzyme activity suggesting that sialic acid and adenosine deaminase would indirectly used as an indicator of invasion of the parasite in the host cells.