Аннотация:At present impacts exerted by heliogeophysic factors on different living organisms are being examined more and more intensely. Over the last decade, it has been detected that meteorological factors play an important role in formation of adaptation mechanisms in living systems. Sun and earth interaction is also known to directly influence rheological properties of human blood, both in a healthy body and in case there are chronic non-communicable diseases. Given that, impacts exerted by “cosmic weather” on living organisms, people in particular, are a stimulus to perform profound studies on reactions occurring as a response to effects produced by solar and geomagnetic activity, first of all, solar flares and magnetic storms.At present the most widely used approach to determining influences exerted by the Earth magnetic field on biological systems involves searching for correlations between different parameters of living organisms functioning and geomagnetic indexes.Our research goal was to assess dependence between enzymatic activity of antioxidant protection system, exemplified by superoxide dismutase (SOD) and catalase, and geomagnetic field disturbances.The research focused on examining blood samples taken from conditionally healthy volunteers living in Nizhniy Novgorod region. SOD and catalase activity were determined in blood erythrocytes with spectrophotometry. Geomagnetic disturbances force was determined as per planetary Kp-index value.The research established a statistically significant correlation between SOD and catalase activity and a value of geo-magnetic field disturbance; this correlation allows making an indirect assumption that geomagnetic conditions directly influence superoxide radical production in a body.Therefore, a change in superoxide radical production is a way for the geomagnetic field to influence living organisms. Activation of free radical oxidation can make for both occurrence and more intense clinical course of several diseases (especially cardiovascular and neuropsychic ones). So, in future it is advisable to assess reactivity of antioxidant protection system as a response to geomagnetic fluctuations in case there are pathologic changes in a body.