You don't give me a lot of information to go on here, but I'll do my best. Curled leaves could be a symptom of a number of different ailments, but the most common is Powdery Mildew. If the leaves have a whitish covering on them, it's most likely this fungal disease. To combat, you'll need to spray every 7 to 10 days with a rose fungicide. This problem is common in the spring when the weather is wet and cool. Also, be sure your plants have plenty of air circulation and they aren't planted too close together and that you never water your roses from above. Drip irrigation is best for roses. Again, without seeing the leaves I can only guess, but since this is early spring that's my guess."