The aim of this work was to trace differences in magnesium and calcium concentrations (both total and ionic form) between goats which were in late pregnancy and lactating goats. The study involved 30 goats. Blood samples were taken three times from each goat. Total concentrations of magnesium and calcium were determined with the colorimetric methodand (A – 1.581 mmol dm–3; B – 2.052 mmol dm–3; C – 2.112 mmol dm–3). Ionic formof calcium based on using ionselective analysis (A – 1.219 mmol dm–3; B – 1.126 mmoldm–3; C – 1.123 mmol dm–3). The study showed that mean value of both the total of calcium from each goat didnot reach the reference level for this species. Ionic form of calcium was within the leverlimit of the physiological norm.The content of magnesium in all the groups was within the range of reference concentrations (A – 1.051 mmol dm–3; B – 1.165 mmol dm–3; C – 1.117 mmol dm–3).