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LDPE plastics are polymers that are widely used because of their waterproof, flexible and affordable characteristics. This study aims to degrade LDPE plastic with temperature and pH variations using biotechnology by a mixed cultures of Thiobacillus sp. and Clostridium sp. bacteria. This mixed bacterial cultures are grown in the growth media of Stone Mineral Salt Solution (SMSs) with a batch system. Analysis of Gravimetric method is used to find out the difference in weight of LDPE plastics and Fourier Transform Red Infrared Spectroscopy (FTIR) is used to determine the change of functional groups. To obtain optimum conditions that produce the highest degradation, temperature variations (oC) 25, 30, 35 and pH 5, 7, 9 were done. Optimum removal of LDPE occurs at 30oC with acidity (pH) 7. It shows that mixed cultures of Thiobacillus sp. and Clostridium sp. bacteria has the ability to degrade LDPE plastics with a percent removal reached 10-15%.