Self esteem merupakan suatu penilaian individu yang mengarah pada evaluasi diri terhadap hasil yang dicapai dipengaruhi oleh sikap, interaksi, penghargaan, dan penerimaan orang lain terhadap individu. Untuk mengukur self esteem dalam penelitian ini menggunakan kuesioner self esteem yang memiliki nilai validitas butir total dengan nilai R sebesar 0,220 dan reliabilitas sebesar 0,945, maka dapat disimpulkan bahwa kuesioner self esteem reliabel dan layak digunakan sebagai instrumen penelitian. Pe- nelitian ini bertujuan untuk mengetahui keefektifan konseling kelompok rational emotive behavior untuk meningkatkan self esteem siswa SMA. Jenis penelitian ini adalah kuantitatif dengan desain penelitian Experiment Pretest and Posttest Control Group Design. Data dianalisis dengan uji statistik nonparametrik Two Independent Sample Test Mann Whitney U. Hasil hipotesis diperoleh nilai Z sebesar -2,120 dan angka Asymp. Sig. (2-tailed) yaitu 0,034 yang berarti lebih kecil dari taraf nyata (a/2=0,05), maka H ditolak, artinya konseling kelompok rational emotive behavior efektif untuk meningkatkan self esteem siswa SMA. Penelitian dilaksanakan mulai dari bulan Februari sampai dengan Juli 2018, yang bertempat di SMA Negeri 1 Kutorejo. Berdasarkan hasil penelitian disampaikan saran, (1) bagi guru Bimbingan dan Kon- seling dapat menerapkan layanan konseling kelompok rational emotive behavior sebagai alternatif untuk meningkatkan self esteem siswa; (2) bagi peneliti selanjutnya dapat menerapkan konseling rational emotive behavior pada aspek psikologis yang lain maupun menggunakan teknik yang berbeda dalam layanan konseling kelompok sehingga akan diperoleh wawasan tambahan.
Kata-kata kunci: konseling kelompok rational emotive behavior, self esteem, siswa SMA

Self-esteem is an individual assessment that leads to self-evaluation of the results achieved, which are influenced by attitudes, interactions, rewards, and acceptance of others towards the individual. To measure self-es- teem in this study using a questionnaire of self-esteem that has a value of total item validity with an R-value of 0.220, and reliability of 0.945, it can be concluded that the questionnaire is reliable and feasible to use as a research instrument. This study aims to determine the effectiveness of the rational emotive behavior group counseling to improve self-esteem of high-school students. This type of research is quantitative with the design of Experiment Pretest and Posttest Control Group Design. Data were analyzed by two nonparametric statistical test`s Independent Mann-Whitney U Sample Test. The results of the hypothesis obtained by the Z value of -2.120 and Asymp numbers. Sig. (2-tailed) which is 0.034, which meant it is smaller than the real level (a/2=0.05), then Ho is rejected, meaning that the counseling of rational emotive behavior groups is effective to improve self-esteem of high-school students. The research was carried out starting from February to July 2018, which took place at SMA Negeri 1 Kutorejo. Based on the results of the research, researchers give suggestions for (1) teacher of Counseling Guidance could apply this rational emotive behavior group counseling as an alternative strategy to improve students' self-esteem; (2) furthermore, researcher could apply rational emotive behavior counseling on the other psychological aspects or using different techniques for group counseling, so they could learn new knowledge.
Keywords: rational emotive behavior groups counseling, self-esteem, senior high-school students