Straipsnyje nagrinėjama svarbiausių žemės ūkio augalų – žieminių kviečių (Triticum aestivum L.) ir vasarinių miežių (Hordeum vulgare L.) – tikėtini derlingumo pokyčiai besikeičiančio klimato sąlygomis. Derlingumui prognozuoti panaudotas kompiuterinis modelis DSSAT v4.0.2.0, kuriuo remiantis sumodeliuoti tikėtini jo pokyčiai pagal skirtingus klimato kaitos scenarijus. The main aim of this study was to estimate the effect of changing climate for cereal crop – spring barley (Hordeum vulgare L.) and winter wheat (Triticum aestivum L.). For this reason in our study was used the most popular computer model DSSAT v4.0.2.0 for simulation of cereal crop yield. The model DSSAT was used in many countries in many different climate conditions. The results of study showed, that temperature could increase from 2 by 6.3 oC. Also will change the regime of precipitation – it will increase in winter and decrease in summer time. According these results we choose these scenarios for simulation of spring barley – the air temperature increase 1, 2, 3 or 4oC and the rainfall increase or decrease 15, 30, 45 mm. For simulation of winter wheat yield was chosen the same increase of temperature, and the rainfall increase or decrease – 30 and 60 mm during vegetation season. The result of our study showed if the temperature will increase and the amount of rainfall decrease it will have negative influence for yield of spring barley and less negative for winter wheat. The increase of temperature will reduce the cereals crop vegetation period.