Some problems were found in the alpha source calibration. Two of such problems are discussed in this paper: 1) distribution of the alpha radiation dose on an area of lonun diameter was seriously non-uniform

the non-uniformity was due to poor quality of the 244Cm source used; 2) the offset dose could not be ignored for some irradiators. The offset doses for twokinds of beta irradiators have been determined

and the calculation equation for the dose was derived.