The purpose of this study was to analyze laboratory instructions in a secondary school science with an analysis instrument on science laboratory instruction. For its purpose, we used an instrument that analyzes three dimensions of the secondary laboratory instructions. This analysis instrument was composed of 3 categories (the aim of the laboratory activity, interaction, and inquiry process) which are spread into 20 sub-categories, and its validity was checked by four science educators with factor of 0.89. For its purpose, 21 sessions of lab instructions were video-recorded and transcribed. According to the results, in the aims category, the instructions mainly focused on two aims; acquiring the declarative knowledge and increasing attitudes toward science. In the interaction category, some of the observations made were that the teachers's questions could not gather the students' divergent thinking, their directive instructions were centered around themselves rather than giving opportunities for students to be centered within laboratory activities, and students' interaction were rarely shown. Therefore, interaction was classified as level I. In the inquiry process, presenting phenomenon or questionings about the subjects were little observed, and students' hypothesizing and predicting were almost nonexistent. Most of the activity designs within lab session were given from the teachers' directions or worksheets, and students solely focused on data collecting and recording. Hence, inquiry process were classified level I.