To provide a microbial pesticide composition of which an active ingredient is stable even after long term storage at room temperature, and maintaining sufficient plant disease controlling effect.SOLUTION: There are provided a stabilization method of microbial pesticide, including a process for adjusting pH to 3.0 to 5.0 on a vulture medium of Bacillus bacteria, a process for mixing calcium chloride of 1 mass% or more and less than 5 mass% with the microbial pesticide, and a process for freeze drying or spray drying the same, a microbial pesticide composition containing Bacillus bacteria and calcium chloride, and a manufacturing method therefor.SELECTED DRAWING: None【課題】室温で長期間保存しても有効成分が安定で、十分な植物病害防除効果を持続する微生物農薬組成物を提供する。【解決手段】バチルス（Bacillus）属細菌の培養液について、ｐＨを３．０～５．０に調整する工程と、塩化カルシウムを微生物農薬に対して１質量％以上５質量％未満混合する工程と、凍結乾燥またはスプレードライする工程を含む微生物農薬の安定化方法、バチルス（Bacillus）属の細菌と塩化カルシウムを含有する微生物農薬組成物及びその製造方法。【選択図】なし
