<![CDATA[Abstract: This Classroom Action Research (CAR) aims to improve the volleyball underhand serve skills of sixth-grade students at SD Negeri 1 Mrentul through a directed training method. The research was conducted in two cycles involving 19 students. Data were obtained through practical tests and direct observation. The results showed an increase in students' abilities in aspects of movement mechanics and psychomotor skills, such as standing balance, ball throwing, and arm swing accuracy. The average student score increased from 52.50 in the pre-action to 68.53 in Cycle I and 82.42 in Cycle II. The percentage of classical completion also increased from 36.84% to 63.16%, then reached 89.47% in Cycle II, exceeding the target success rate of 80%. The N-Gain value of 0.65 indicates the method's effectiveness in the medium to high category. Thus, the directed training method has proven effective in improving volleyball underhand serve skills. Keywords: underhand serve, structured drill, volleyball. Abstrak: Penelitian Tindakan Kelas (PTK) ini bertujuan meningkatkan kemampuan servis bawah bola voli siswa kelas VI SD Negeri 1 Mrentul melalui metode latihan terarah. Penelitian dilaksanakan dalam dua siklus dengan melibatkan 19 siswa. Data diperoleh melalui ujian praktik dan observasi langsung. Hasil penelitian menunjukkan peningkatan kemampuan siswa pada aspek mekanika gerak dan keterampilan psikomotorik, seperti keseimbangan posisi berdiri, lemparan bola, dan akurasi ayunan tangan. Nilai rata-rata siswa meningkat dari 52,50 pada pratindakan menjadi 68,53 pada Siklus I dan 82,42 pada Siklus II. Persentase ketuntasan klasikal juga naik dari 36,84% menjadi 63,16%, lalu mencapai 89,47% pada Siklus II, melampaui target keberhasilan 80%. Nilai N-Gain sebesar 0,65 menunjukkan efektivitas metode pada kategori sedang hingga tinggi. Dengan demikian, metode latihan terarah terbukti efektif meningkatkan kemampuan servis bawah bola voli. Kata Kunci: servis bawah, latihan terarah, pendidikan jasmani, bola voli.]]>
