penalty constant
2.In chapter one, we introduce the Erlang(2) risk process with constant interest force and give the definition of the probability of ruin, the surplus immediately before ruin, the deficit at ruin, the joint distribution of the surplus immediately before ruin and the deficit at ruin, the expected discounted penalty at ruin respectively.
3.This dissertion mainly study the Erlang(2) risk model with constant interest force, we consider some important distributions and rusults: the non-ruin probability, the surplus immediately before ruin, the deficit at ruin, the joint distribution of the surplus immediately before ruin and the deficit at ruin, the expected discounted penalty at ruin and so on.

