Nowadays, there is an intention to increase the flax fiber exportation as well as local industry which depend to a great extent on the fiber quality. The degree of retting is the single most important factor govering the mechanical extracting of the fiber from the stem. So, it is very important to improve retting methods for the flax straw. In Egypt, two mechanized systems for extracting flax fiber from the stem (partial mechanized system and complete mechanized system). The main aim of this research was to optimize the necessary recommendations which are needed to best flax fiber extraction with a low cost, energy and high efficiency. The results showed that the proper system to execute the extracting operation of flax fiber under local condition is the complete mechanized system, which give the highest values of flax fibers separation percentage of (96.30%), flax fiber length of (101.00 cm.), long fiber percentage of (23.42%), Fiber fineness of (285.45 mm/mg.), long fiber strength of  (28.42 mm.N/mg.), the lowest values of specific energy for separating one Mg of flax straw of (40.06 kW.hr /Mg) and criterion costs of (504.59 LE/Mg).