This experiment was carried out in Bandargah Station in Bushehr province. Peneaus semisulcatus larvae were fed on Spirulina platensis as supplementation microalgae. In order to use spirulina platensis in this study, we have to produce biomass and dry production of this microalga. Determination of length and survival rate of Peneaus semisulcatus larvae was carried out as the objective of the study. Treatments including Z plus (as a supplementation without spirulina), M.C.F (as an imported enriched spirulina), the powder combination of Spirulina platensis with Z plus and Spirulina platensis as live food were compared to Cheatocerus microalgae as a control. The experiment was carried out from nauplii stage to early post larvae. The results of the experiment indicated that the powder combination of Spirulina platensis with Z plus treatment has the most survival rate (76.5%). The maximum of length (4.3mm) observed in control (Cheatocerus spp.).The maximum mortality was observed in zoa stage in spirulina microalgae treatment, because the spiral filamentous of spirulina sp.was large.