The present paper reports on comparative studies of R-phycoerythrin (R-PE) from 30 species of the red seaweeds in Bangiophyceae and in Florideophyceae from Qingdao. The measured absorption spectra show that R-PE from these red seaweeds have two spectral types, namely type I having two absorption peaks and type II having three absorption peaks. 9 specise of a lower red seaweed belonging to Bangiophyceae are all type I R-PE. 3 species of a higher red seaweed belonging to Florideophyceae are also type I R-PE. The remaining 18 species are all type II R-PE. According to the distribution of two types of R-PE in red algae, an evolutionary trend from type I R-PE to type II R-PE can be seen, but this evolutionary process is more complicated and without a definite line of demarcation between the two spectral types of R-PE. The occurrence of two types of R-PE in red algae is of taxonomic significance. The present paper reports on comparative studies of R-phycoerythrin (R-PE) from 30 species of the red seaweeds in Bangiophyceae and in Florideophyceae from Qingdao. The measured absorption spectra show that R-PE from these red seaweeds have two spectral types that type I having two absorption peaks and type II having three absorption peaks. 9 specise of a lower red seaweed belonging to Bangiophyceae are all type I R-PE. 3 species of a higher red seaweed belonging to Florideophyceae are also type I R-PE. The remaining 18 species are all type II R-PE. According to the distribution of two types of R-PE in red algae, an evolutionary trend from type I R-PE to type II R-PE can be seen, but this evolutionary process is more complicated and without a definite line of demarcation between the two spectral types of R-PE. The occurrence of two types of R-PE in red algae is of taxonomic significance.