The technique to arrest Drosophila melanogaster embryos at a specific developmental stage is desirable to various applications that require a population with relatively uniform amount of DNA. One example is to measure the allelic frequencies using pooled sequencing (Wei et al. 2017). To achieve this, RNAi constructs activated by Gal4 proteins were used to knock down genes essential to D. melanogaster embryonic development. I tested the arresting efficiencies of six different RNAi constructs. Four of which had an arrest rate greater than 97.3% (trk-pNP, dl-pNP, dl-UASz, tor-UASz; the names are defined in Method section). I also found strong evidence indicating that the Gal4 gene locus was affecting the arrest rate. Several constructs also showed evidence that the age of the female expressing them could be an affecting factor. In spite of this, there was sometimes high variations between results from different replicas of the same RNAi constructs, which could be either due to random environmental factors or polymorphisms within the same fly lines. Further studies would therefore be needed to better address this internal variation, and to generalize the technique for D. melanogaster strains with different genetic backgrounds.