diff --git a/crc/crc_poly.c b/crc/crc_poly.c
new file mode 100644
index 0000000..a44753e
--- /dev/null
+++ b/crc/crc_poly.c
@@ -0,0 +1,104 @@
+/*
+** The crc32 is licensed under the Apache License, Version 2.0, and a copy of the license is included in this file.
+**
+**Author:Wang Yaofu voipman@qq.com
+**Description: The source file to calc crc poly.
+*/
+#include <stdlib.h>
+#include "crc_poly.h"
+
+// LSB-first
+uint8_t crc8_poly_lsb(uint8_t poly, uint8_t value) {
+    uint8_t crc;
+    uint8_t j;
+
+    crc = value & 0xFF;
+    for (j = 8; j > 0; --j) {
+        if (crc & 1) {
+            crc = (crc >> 1) ^ poly;
+        } else {
+            crc = crc >> 1;
+        }
+    }
+    return crc;
+}
+
+uint8_t crc8_poly_msb(uint8_t poly, uint8_t value) {
+    uint8_t crc;
+    uint8_t j;
+    uint8_t mask = 0x80;
+
+    crc = value & 0xFF;
+    for (j = 8; j > 0; --j) {
+        if (crc & mask) {
+            crc = (crc << 1) ^ poly;
+        } else {
+            crc = crc << 1;
+        }
+    }
+    return crc;
+}
+
+// LSB-first
+uint16_t crc16_poly_lsb(uint16_t poly, uint16_t value) {
+    uint16_t crc;
+    uint16_t j;
+
+    crc = value & 0xFF;
+    for (j = 16; j > 0; --j) {
+        if (crc & 1) {
+            crc = (crc >> 1) ^ poly;
+        } else {
+            crc = crc >> 1;
+        }
+    }
+    return crc;
+}
+
+// msb first
+uint16_t crc16_poly_msb(uint16_t poly, uint16_t value) {
+    uint16_t crc;
+    uint16_t j;
+
+    crc = value & 0xFF;
+    for (j = 16; j > 0; --j) {
+        if (crc & 0x8000) {
+            crc = (crc << 1) ^ poly;
+        } else {
+            crc = crc << 1;
+        }
+    }
+    return crc;
+}
+
+// LSB-first
+uint32_t crc32_poly(uint32_t poly, uint16_t value) {
+    uint32_t crc;
+    uint16_t j;
+
+    crc = value & 0xFF;
+    for (j = 8; j > 0; --j) {
+        if (crc & 1) {
+            crc = (crc >> 1) ^ poly;
+        } else {
+            crc = crc >> 1;
+        }
+    }
+    return crc;
+}
+
+// LSB-first
+uint64_t crc64_poly(uint64_t poly, uint16_t value) {
+    uint64_t crc;
+    uint16_t j;
+
+    crc = value & 0xFF;
+    for (j = 8; j > 0; --j) {
+        if (crc & 1) {
+            crc = (crc >> 1) ^ poly;
+        } else {
+            crc = (crc >> 1);
+        }
+    }
+    return crc;
+}