In the present study, combustion of organic dust flame in air in counter-flow system is investigated. Lycopodium is considered as fuel particle in the present research. The flame structure is assumed to consist of a vaporization zone, a reaction zone and a post flame zone. Then the governing equations are applied for each zone and solved analytically. The predicted flame speed in terms of equivalence ratio is in agreement with the results of a previous study. In addition, the variation of the flame position with the initial radius, equivalence ratio are studied.