This study analyzes the KPPU Decision Number 03/KPPU-L/2020 pertaining to the case of predatory pricing in South Kalimantan’s cement industry. In this particular case, the Reported is a company that enters the cement market in 2015, and rapidly increases its market share while the other competitors experience a decline. The analysis reveals that the evidence supports the proof of predatory pricing through the Pre-Cost Test and Recoupment Test approaches, and also by implementing the Rule of Reason approach. This predatory pricing practice has a negative impact that widespreads and lessens fair competition, harms consumers, inhibits innovation, and potentially creates monopoly. A sharp decline of price forces other competitors to exit the market and the rest to experience financial loss. The implication is not only suffered by business actors, but also by the economy as a whole. The government and supervisory bodies have to supervise, apply effective test, and create collaboration between business actors, the government, and consumers in order to maintain fair competition. The importance of the Rule of Reason approach is also emphasized to prevent excessive scrutiny towards legitimate business practices. It is expected that these steps will be able to create a business environment that is just, innovative, sustainable, and one that protects consumers and public interest altogether.Keywords: Analysis, Negative Impact, Cement Industry, Predatory Pricing, KPPU Decision AbstrakStudi ini menganalisis Putusan Nomor 03/KPPU-L/2020 tentang kasus predatory pricing di industri semen Kalimantan Selatan. Dalam kasus ini, terlapor adalah perusahaan baru yang memasuki pasar semen pada 2015, dengan cepat meningkatkan pangsa pasarnya sementara pesaing mengalami penurunan. Analisis mengungkapkan bahwa bukti mendukung pembuktian predatory pricing melalui pendekatan pre-cost test dan recoupment test, dengan menerapkan pendekatan rule of reason. Praktik predatory pricing ini memiliki dampak negatif yang meluas, termasuk penurunan persaingan sehat, merugikan konsumen, menghambat inovasi, dan potensial menciptakan monopoli. Penurunan harga yang tajam mengancam pesaing keluar dari pasar dan pesaing lain mengalami penurunan pendapatan. Implikasinya tidak hanya pada pelaku usaha, tetapi juga ekonomi secara keseluruhan. Pemerintah dan lembaga pengawas harus melakukan pengawasan, menerapkan uji efektif, serta kolaborasi antara pelaku usaha, pemerintah, dan konsumen untuk menjaga persaingan sehat. Pentingnya pendekatan rule of reason juga ditekankan untuk menghindari penilaian berlebihan terhadap praktik bisnis yang sah. Diharapkan langkah-langkah ini mampu menciptakan lingkungan bisnis adil, inovatif, dan berkelanjutan, melindungi kepentingan konsumen serta masyarakat secara menyeluruh.Kata Kunci: analisis, dampak negatif, industri semen, predatory pricing, Putusan KPPU.