Optical fiber is broadly used in telecommunication purpose instead of copper wire because of its very high bandwidth and low transmission loss. But it has many chances to loss the transmitting signal. There is always some types of imperfections present at fiber optic connections that causes some loss of signal. It is the amount of optical power lost at fiber optic connections that is a concern of system designers and such type of losses are called splice loss. A fiber optic splice is a permanent fiber joint whose purpose is to establish an optical connection between two individual optical fibers and it is required for long distance communication. So for long distance communication it is necessary for reducing transmitted signal loss. When two fibers are spliced together various types of splicing errors can occur. But significant power loss occurs for transverse offset and tilt. We write the result of a simulation study on the splice of a single mode step index fiber in this book.