Experimental investigations of tsunami run-up and erosion area on permeable slope beaches were carried out in a laboratory channel. A natural sandy beach was configured with a diameter of 0.35 mm and specific gravity of 2.63. The slope of the beach was 1:5. Furthermore, different types of armor units, the diameter and specific gravity of which varied in the range of 10-13.8 mm and 2.318-2.289, respectively, were placed on permeable slope beaches. Experiments for impermeable beaches were performed for comparison with previous investigations and it is seen that the results agree with each other. Tsunami run-up heights were investigated for permeable (armored and not armored) beaches and empirical formulas for were suggested. From the results of these experiments it was observed that armor units causes a decrease about 50% in run-up height. In addition to these, coastal profile changes formed by tsunami was examined and an empirical formula giving dimensionless erosion area parameter for without armor area is suggested. Al so the relation between run-up height and erosion area is expressed with a formula. (C) 2005 Elsevier Ltd. All rights reserved.