As a language for communication, students have to be accustomed to speak English orally in the classroom even in the simplest way, such as greeting, answering, expressing ideas, giving responses, and other simple expressions. This research focused on the affective factors that cause inhibition as one of the problem in speaking English. This was a descriptive research that used quantitative approach. The subject of this research is 62 students from X MIA 1 and X IS 2 of SMA Negeri 9 Banjarmasin. The data of this research were about affective factors that cause student inhibition in speaking English. Questionnaire was used to collect the data.  From the result of the questionnaire it can be found the most frequent factor that cause students inhibition is shyness followed by self-confidence. Besides inhibition, students also had low or uneven participation in speaking activity in the classroom. Most of the students rarely asked to have conversation in English with their friends. To overcome inhibition the teachers have to be friendly, helpful and cooperative to make students feel comfortable when speaking in the class, as well as reminding students not to worry about making mistakes and giving the students clear instructions and sufficient guidance.