For the analysis of the relationship between carrier transfer properties and morphologies of light-emitting polymers, it is important to investigate carrier transfer pathways. We developed a novel computational method for analysis of carrier transfer pathways by the combination of tightbinding quantum chemistry calculation with Monte Carlo method. This novel method was applied to the prediction of electron transfer in poly(9,90- dioctylfluorene)(PDOF), which is known as a blue light-emitting polymer. We successfully investigated the electron transfer pathways in PDOF films. We found that the electron transfer mainly occurs in an intra chain, but the inter chain electron transfer was also observed between aromatic rings whose distance was less than 4.0Å.