Red swamp crayfish, Procambarus clarkii have immigrated since 2009 into one habitat of the Japanese newt Cynops pyrrhogaster that we observed from 1999 to 2002 in Hiroshima Prefecture, Japan, so we studied the habitat again in December 2012. The observed number of individuals of C. pyrrhogaster in 2012 and their catch per unit effort as relative density tended to decline, and 93.9% of males and 72.7% of females showed injury. In another habitat that P. clarkii has invaded since 1993, C. pyrrhogaster showed low frequency of observation and many injured individuals from 1997 to 2002.