Coccinella transversalis Fab. is a common predator or Aphis craccivora Koch (Homoptera:Aphldidae), on field beans in Manipur. The biology of the predator was studied In the laboratory (at 18.23 ± 1.60 °C and 55.54 ± 2.38 % R.H.). The life cycle from egg to adult was completed in 38-45 days. Incubation period took 8-10 days. The mean duration of I,II,III and IV larval Instars, prepupn and pupa were 4.69, 3.92, 5.0, 7.69, 2.62 and 8.6 days respectively. The total larval period ranged from 19 to 23 days. The total consumption by a single larva was 526 aphids. Important morphological characters and size or developmental stages are given for easy Identification in the field.