  In this paper, we introduce the cumulative past information generating
function (CPIG) and relative cumulative past information generating function
(RCPIG). We study its properties. We establish its relation with generalized
cumulative past entropy (GCPE). We defined CPIG stochastic order and its
relation with dispersive order. We provide the results for the CPIG measure of
the convoluted random variables in terms of the measures of its components. We
found some inequality relating to Shannon entropy, CPIG and GCPE. Some
characterization and estimation results are also discussed regarding CPIG. We
defined divergence measures between two random variables, Jensen-cumulative
past information generating function(JCPIG), Jensen fractional cumulative past
entropy measure, cumulative past Taneja entropy, and Jensen cumulative past
Taneja entropy information measure.
