The time dependent resistivity associated with the intercalation of alkali metal atoms and iodine molecules into "carbolite", the quasi one dimensional carbon crystal, was measured at a constant temperature. After maintaining a value suitable for semiconducting behavior during a long time of intercalation, the resistivity suddenly decreased by several orders of magnitude, corresponding to a metallic conduction. Alkali atoms or halogen molecules randomly attacked the triangular lattice of the carbon chains and become located at the inter-chain sites. The intercalants of the nearest neighbor sites formed local clusters. As the intercalation proceeded, clusters aggregated to make larger clusters. When aggregation reached such an extent that the cluster sizes were comparable to the sample size, conducting paths throughout the sample opened up. This means that the resistance changes from semiconductive to metallic. This change occurs like an electronic phase transition as the nature of a percolation process.