Discrete data are frequently encountered in the entomological and pathological science of agriculture. The relationship between dose and response has been tested by using the probit and logit anaysis in this book. From the analysis, LC50, LT50, LD50, goodness of fit, anlysis of deviance, etc were tested. Rsults revealed that discrete dose-response data on entomological study is best fitted by using either log-probit or log-logit regression rather than probit and logit regression only. The detainled on work is present inside the book. I hope it help more for the professionals, researcher, students who involved basically in entomology and pathology of agriculture.