The cellular DNA contents of Channa maculata, C.argus and their reciprocal hybrids (C.maculata ♀×C.argus ♂, C.argus ♀×C.maculata ♂) were assayed by using a flow cytometer with the DNA of chicken red blood cells (2.5 pg/2c, 2c:diploid) as a standard. The DNA contents of the 4 species of fish are 1.488±0.035 pg/2c (C.maculata ♀), 1.489±0.034 pg/2c (C.argus ♂), 1.522±0.077 pg/2c (C.maculata ♀×C.argus ♂), and 1.520±0.033 pg/2c (C.argus ♀×C.maculata ♂) respectively. Comparing the DNA contents of the 4 species of fish, it was showed that there was no significant difference between C.maculata and C.argus (P>0.05), and the similar result was obtained between their reciprocal hybrids (P>0.05), but there was significant difference between reciprocal hybrids and their parents (P<0.05). The DNA contents of the reciprocal hybrids are more than those of their parents, which may be used for hybrid identification.