The current study examined whether and how the variety of episodic contexts influences the integration of novel words into semantic network via thematic and taxonomic relations in a semantic priming task with event-related potential (ERP) technique. The novel words were acquired from discourses containing either single or multiple episodes. We found that corresponding concepts, targets thematic-related to learning episodes (Experiment 1) and taxonomic-related targets (Experiment 2) elicited semantic-priming N400s/LPCs effects compared to the unrelated targets in both conditions, whereas the targets thematic-related to unlearned episodes (Experiment 1) and feature-related targets (Experiment 2) elicited semantic-priming N400s/LPCs effects only in the multiple episodic condition. These results indicated that only the novel words learned from variable episodes could successfully prime thematically related words in unlearned episodes and feature-related words. Our findings suggest that the variety of episodic contexts contributes to establishing more stable and richer semantic representations of the novel words.