DS86 is a calculation code system for the estimation of the radiation dose of atomic bomb survivors at Hiroshima and Nagasaki. The DS86 calculation process is as follows: 1. Compute free-field radiation environment: radiation transport calculation can be done for the free air field at Hiroshima and Nagasaki. 2. Compute shielded radiation environment: depending on each shielding situation, the shielding can be calculated by using either the Nine-Shielding Parameter or the Globe Shielding Data. 3. Compute radiation environment at the organ site: organ kerma and fluence spectra can be calculated using a transport calculation code depending on each survivor sex, age, orientation and posture.