We are suggesting a blood transfusion system based on various data mining algorithms. We have applied and compared various algorithms such as Decision tree, Random forest and logistic regression, before and after applying GRA. The algorithm with most efficiency will be used to develop a system for predicting the nature of a blood donor, based on past data of donation. The prediction will be useful at various blood donation camps for contacting the donors, in case of a requirement. © 2019 IEEE.