The biodegradability of plastic sheetsmade ofmixed proteins Â LDPE blend was investigated. Mixed proteins Â LDPE blend based plastic sheets were subjected to microbial degradation using Pseudomonas aeruginosa. At regular interval of 4 days, culture growths and soluble protein concentrations have been measured throughout the biodegradation study. Results from the biodegradation showed that, plastic sheets prepared frommixture of soybean, castor and rapeseed proteins Â LDPE blend could support the growth of P. aeruginosa. Biodegradable plastic sheetwith composition (70:10:20mixed proteins&10%LDPE) degradedmuch faster than other eight biodegradable plastics sheets under the conditions examined.