Drought stress is considered one of the main factors that reduce plant growth, development and production. Therefore, studying plants during drought stress is highly useful to discover the newly gained characteristics of plants. The potato is considered one of the most important crop with economic value in Egypt and over the whole world. The main target is the proline-rich protein extracted from potato plants under drought stress. A stress experiment was applied to two potato (Solanum tuberosum L.) cultivars Desiree and Diamante. The stress experiment was conducted by poly-ethylene glycol (PEG) 4000; the used water potentials were: zero (control), (PEG 2%), (PEG 4%) and (PEG 8%), after drought stress, the solutes accumulation in the two potato cultivars were determined. Increasing drought stress through elevating PEG decreased leaf area as well as shoot and root lengths. Incontorary, the chlorophyll and proline contents increased with increasing PEG treatments. The proline-rich protein gene was cloned to the pGEM-T Easy vector and was submitted to the gene bank to be used later for enhancing drought resistance in other cultivars.