It is clear that the effective information increases along with the increase of organismal phenotypic complexity defined by taxonomy, evolution, and intuition. The simpler the organism, the lower the I value. The more complex the organism, the higher the I value. The effective information in viruses is between 10 3~1 0 5 bits, while in bacteria is between 10 6~1 0 7 bits, and in eukaryotes between 10 7~1 0 8 bits. For multicellular organisms, the effective information increases from 4.68e7 bits of placozoa to 8.38e8 bits of human beings. Worm, insects, amphioxus, fish, frog, bird falls in between. These results are consistent to other observations with the number of cell types [22] , and the number of miRNA families [23] . Aburomia et al calculated the morphological complexity of 21 extant higher-order chordate groups based on the presence or absence of 479 morphological characters [24] . Their results are consistent to ours. Therefore, the effective information can be used as a quantitative measure of organismal phenotypic complexity from the simplest viruses to the most complex human beings. While limited by the incomplete data presently available, some results may not be so accurate, but the approximate range will remain true. When data become more complete and accurate, more precise calculation can be conducted.