Practicum is one of learning method. One of the facilities needed in practicum is a practical guidance. One of learning approach that can support practicum activities is guided inquiry. The purpose of this study was to develop an inquiry-oriented biology practicum guide for high school grade XI semester 2 and find out the validity criteria of the practicum guide. This research was a Research and Development which used Plomp development model, which consists of three stages: preliminary research phase, development phase, and assessment phase. The validity of guided inquiry-oriented biology practice guides was obtained from the results of validation using expert validation sheet by 5 experts. The results showed that the didactic requirement got 86.43% with very valid criteria, the construction requirements got 83.13% with very valid criteria, technical requirements got 82.50% with very valid criteria, the language requirement got 84, 17% with very valid criteria and the overall average of all four conditions gets 84.04% with very valid criteria. Inquiry-oriented biology practicum guide has been successfully developed with validity criteria is very valid and is expected to be a guideline for practicum guides that can help to improve students cognitive, affective and psychomotor competence.