Two kinds of photo-monitoring strips, Rhodamine B (dyestuff) and litharge (pigment) strips, have been developed as simple indicators for accumulated amounts of radiation energy. After irradiation with monochromic rays ranging from 235nm to 699nm, these strips were examined for change in their original colors at several time intervals. Litharge strips quickly discolored with light shorter than 441nm, but were fairly stable with light longer than 498nm, indicating their being unsuitable as photo-monitoring strips for the visible region. On the other hand, Rhodamine B strips were fairly sensitive to radiation ranging from 388nm to 596nm, indicating their suitability as photo-monitoring strips. The author also tested the two strips using a fluorescent lamp which does not emit uv rays below 380nm and indicated the advantages of the use of two kinds of strips. -- AATA