The purpose of this research is to analyze two translation versions of modal auxiliary verbs in the novel The Old Man and the Sea by Ernest Hemmingway into Indonesian. The research is comparative study since it involves two translation novels in Indonesian version converted by two different translators; Yuni Kristianingsih Pramudhaningrat and Dian Vita Ellyati. The objectives of this research are to find out the translation technique used by both translators and the effect of translation technique on translation quality in term of accuracy and acceptability. The research is a descriptive-qualitative. The data of this research are modal auxiliary verbs in the novel The Old Man and the Sea and two Indonesian translated versions. The informants or raters are also involved. The methods of data collection are content analysis and interview. The content analysis method is applied to obtain translation technique. The interview method is intended to gain more information related to translation quality. The result of this research reveals that both translators use six translation techniques; 1) literal, 2) reduction, 3) modulation, 4) established equivalent, 5) amplification, 6) transposition. From the translation quality assessment of modal auxiliary verbs, both translators create acceptable translation. Meanwhile in accuracy aspect Dian Vita Ellyati generates more accurate translation in translating modal auxiliary verbs than Yuni Kristianingsih Pramudhaningrat. In conclusion, Yuni Kristianingsih Pramudhaningrat and Dian Vita Ellyati generate accurate and acceptable translation in rendering modal auxiliary verb. Literal and established equivalent technique contributes to construct more accurate translation. Each of them creates 100% accurate translation from Yuni and 97,92% from Dian . However, reduction technique generates 56% inaccurate translation from Yuni and 84,21% from Dian. So for other translators, they should not delete modal auxiliary meaning, generate too many changes and make unnecessary addition. Keywords: comparative analysis, modality, translation techniques, translation quality