The damage to pear and plum buds was investigated in Mashhad, after an unusual warm weather for a few days period in March 2013 followed by a sudden drop in temperature to -12°C. Frost damages of vegetative and reproductive buds and spur-part below the buds of pear and plum cultivars were investigated based on visual observations. Pear (Pyrus communis L.) cultivars were: ‘William’s’, ‘Bell de june’, ‘Ida’, ‘Spadona’, ‘Koshia’, ‘Domkaj’, ‘Dare Gazi’, ‘Mohamad Ali’, ‘Boheme’, ‘Shekari’, ‘Ghodumi’ and one Asian pear (Pyrus serotina Rehd.). Japanese plum (P. salicina L.) included: ’Shiro’, ’Shams’, ’Computi’) and European plum (Prunus domestica L.) included ’Stanley’,’Early Santa Rosa’, ’Late Santa Rosa’, ’Shablon’, ’Black Diamond’. Electrical conductivity (EC) and proline content were measured in reproductive buds. It was discovered that visual damages were different between cultivars as vegetative pear bud of ‘Ghodumi’ suffered the most damage and in plum cultivars, all parts of ‘Late Santa Rosa’ were the most susceptible. On the other hand, ‘Computi’ had the most resistant reproductive bud and no damage was observed in the other parts. The EC and proline content of ‘Dare Gazi’ were the highest despite the fact that high proline content did not show high resistance which was related to ‘Dare Gazi’ phenological stage.

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