Blood samples were collected from 20 healthy miniature Caspian horses at 37 °C. Isolation of cryoglobulin was performed based on a standard method in present study. Harvested sera were kept at 4 °C for two hours and then examined for cryoglubolin. Four serum samples containing precipitate Suspicious of containing cryoglobulin were selected. Subsequently serum protein electrophoresis was performed on normal serum samples and also on four serum samples containing precipitates using an automated electrophoresis system on cellulose acetate strips. In addition Ig isotypes detection (IgG, IgM and IgA) was performed on both precipitates and serum containing precipitates using single radio immunediffusion method (SRID). A narrow-based peak on gamma region of precipitate acetate cellulose strips was observed. Precipitate concentrations were strikingly higher than normal concentration of serum immuneglobulins. It can be suggested that cryoglobulin concentration in a proportion of Caspian miniature horse is higher than other equides may be in relation with animal susceptibility to neoplasias such as lymphoma and leukemia.