diff --git a/Makefile b/Makefile
index d008f54..e41cee0 100644
--- a/Makefile
+++ b/Makefile
@@ -121,6 +121,7 @@ test/example:
 	${CELL} -d -t riscv tests/examples/switch.cell && ckb-debugger --bin switch${exe} | grep "five"
 	${CELL} -d -t riscv tests/examples/number-literal.cell && ckb-debugger --bin number-literal${exe}
 	${CELL} -d -t riscv tests/examples/to-string.cell && ckb-debugger --bin to-string${exe}
+	${CELL} -d -t riscv tests/examples/pow.cell && ckb-debugger --bin pow${exe}
 	${CELL} -d -t riscv tests/examples/return.cell && ckb-debugger --bin return${exe}
 	${CELL} -d -t riscv tests/examples/named-ret-type.cell && ckb-debugger --bin named-ret-type${exe} | grep "0"
 	${CELL} -d -t riscv tests/examples/func.cell && ckb-debugger --bin func${exe} | grep "999"
diff --git a/pkg/math/pow.cell b/pkg/math/pow.cell
new file mode 100644
index 0000000..c52f052
--- /dev/null
+++ b/pkg/math/pow.cell
@@ -0,0 +1,99 @@
+package math
+
+type uint8 uint8
+type uint16 uint16
+type uint32 uint32
+type uint64 uint64
+type uint128 uint128
+type uint256 uint256
+
+// x ** y
+func (x uint8) pow(y uint64) uint256 {
+	if y == 0 {
+		return 1u256
+	}
+	ret := uint256(x)
+	for i := 1; i < y; i += 2 {
+		ret *= ret
+	}
+	mod := y % 2
+	if mod == 1 {
+		ret *= uint256(x)
+	}
+	return ret
+}
+
+func (x uint16) pow(y uint64) uint256 {
+	if y == 0 {
+		return 1u256
+	}
+	ret := uint256(x)
+	for i := 1; i < y; i += 2 {
+		ret *= ret
+	}
+	mod := y % 2
+	if mod == 1 {
+		ret *= uint256(x)
+	}
+	return ret
+}
+
+func (x uint32) pow(y uint64) uint256 {
+	if y == 0 {
+		return 1u256
+	}
+	ret := uint256(x)
+	for i := 1; i < y; i += 2 {
+		ret *= ret
+	}
+	mod := y % 2
+	if mod == 1 {
+		ret *= uint256(x)
+	}
+	return ret
+}
+
+func (x uint64) pow(y uint64) uint256 {
+	if y == 0 {
+		return 1u256
+	}
+	ret := uint256(x)
+	for i := 1; i < y; i += 2 {
+		ret *= ret
+	}
+	mod := y % 2
+	if mod == 1 {
+		ret *= uint256(x)
+	}
+	return ret
+}
+
+func (x uint128) pow(y uint64) uint256 {
+	if y == 0 {
+		return 1u256
+	}
+	ret := uint256(x)
+	for i := 1; i < y; i += 2 {
+		ret *= ret
+	}
+	mod := y % 2
+	if mod == 1 {
+		ret *= uint256(x)
+	}
+	return ret
+}
+
+func (x uint256) pow(y uint64) uint256 {
+	if y == 0 {
+		return 1u256
+	}
+	ret := uint256(x)
+	for i := 1; i < y; i += 2 {
+		ret *= ret
+	}
+	mod := y % 2
+	if mod == 1 {
+		ret *= uint256(x)
+	}
+	return ret
+}
diff --git a/tests/examples/pow.cell b/tests/examples/pow.cell
new file mode 100644
index 0000000..d6af183
--- /dev/null
+++ b/tests/examples/pow.cell
@@ -0,0 +1,55 @@
+import (
+	"math"
+)
+
+func u8() {
+	a := 10u8.pow(3)
+	if a != 1000u256 {
+		panic("error")
+	}
+}
+
+func u16() {
+	a := 10u16.pow(2)
+	if a != 100u256 {
+		panic("error")
+	}
+}
+
+func u32() {
+	a := 10u32.pow(2)
+	if a != 100u256 {
+		panic("error")
+	}
+}
+
+func u64() {
+	a := 10u64.pow(2)
+	if a != 100u256 {
+		panic("error")
+	}
+}
+
+func u128() {
+	a := 10u128.pow(2)
+	if a != 100u256 {
+		panic("error")
+	}
+}
+
+func u256() {
+	a := 10u256.pow(2)
+	if a != 100u256 {
+		panic("error")
+	}
+}
+
+func main() {
+	u8()
+	u16()
+	u32()
+	u64()
+	u128()
+	u256()
+	return 0
+}
\ No newline at end of file