In this work, we have achieved novel lateral enhancement-mode (E-M) and depletion-mode (D-M) β-Ga 2 O 3 metal-oxide-semiconductor junction field-effect-transistors (MOS-JFETs) featuring a low gate leakage current (I G ) and a large gate swing. Ascribing to the high-quality SiO 2 layer above the P-NiO X /N-Ga 2 O 3 heterojunction (HJ), the I G was suppressed for over 6 orders of magnitudes when compared with the heterojunction FET (HJ-FET). An off-state drain current of ~10 -7 mA/mm was also achieved at elevated temperature (T) up to 200 °C, indicating strong thermal stability of our device. The depletion-mode (D-M) MOS-JFET with source-to-drain spacing (L SD ) of 12 μm demonstrates a breakdown voltage (BV) of 1.32 kV and specific on-resistance (R on,sp ) of 4.4 mΩ∙cm 2 , delivering a high Baliga's power figure of merit (PFOM) of 405 MW/cm 2 . Due to the potential of β-Ga 2 O 3 MOS-JFET in power electronics, these findings offer a compel ling pathway for future high-power and high-efficiency systems.