Abstract:Gamma-ray bursts (GRB) and blazars are luminous point sources in gamma-rays and primary candidates for IceCube neutrinos. The potential spatial and temporal correlations between the IceCube neutrinos and the gamma-ray flares from those sources have called attentions and extensive studies. Due to the low statistics of the observed neutrino events, it is important to interpret the results based on accurate analysis of the sources. Here I will summarize the recent developments on the modeling of GRBs and blazars and especially, the correlation between their gamm-ray and neutrino messengers.