This book can help research students those who are working in the field of biodegradation of textile effluent. This is a preliminary study of fungal isolates in their ability to degrade reactive dyes. According to this, students can pursue their research in molecular aspect of dye degradation and textile effluent treatment in small scale and large scale. Students should come forward to do this type of research which are important to reduce the environmental pollution. I would like to thank my guide Dr. A. Palanisamy, Head, Biological Science, Muthayammal College of Arts & Science, Rasipuram for his support.