diff --git a/id.go b/id.go
new file mode 100644
index 00000000..d36c008b
--- /dev/null
+++ b/id.go
@@ -0,0 +1,97 @@
+package runn
+
+import (
+	"crypto/sha1" //#nosec G505
+	"encoding/hex"
+	"errors"
+	"io"
+	"path/filepath"
+	"strings"
+
+	"github.com/rs/xid"
+	"github.com/samber/lo"
+)
+
+// generateIDsUsingPath generates IDs using path of runbooks.
+// ref: https://github.com/k1LoW/runn/blob/main/docs/designs/id.md
+func generateIDsUsingPath(ops []*operator) error {
+	if len(ops) == 0 {
+		return nil
+	}
+	type tmp struct {
+		o  *operator
+		p  string
+		rp []string
+		id string
+	}
+	var ss []*tmp
+	max := 0
+	for _, o := range ops {
+		p, err := filepath.Abs(filepath.Clean(o.bookPath))
+		if err != nil {
+			return err
+		}
+		rp := reversePath(p)
+		ss = append(ss, &tmp{
+			o:  o,
+			p:  p,
+			rp: rp,
+		})
+		if len(rp) >= max {
+			max = len(rp)
+		}
+	}
+	for i := 1; i <= max; i++ {
+		ids := []string{}
+		for _, s := range ss {
+			var (
+				id  string
+				err error
+			)
+			if len(s.rp) < i {
+				id, err = generateID(strings.Join(s.rp, "/"))
+				if err != nil {
+					return err
+				}
+			} else {
+				id, err = generateID(strings.Join(s.rp[:i], "/"))
+				if err != nil {
+					return err
+				}
+			}
+			s.id = id
+			ids = append(ids, id)
+		}
+		if len(lo.Uniq(ids)) == len(ss) {
+			// Set ids
+			for _, s := range ss {
+				s.o.id = s.id
+			}
+			return nil
+		}
+	}
+	return errors.New("failed to generate ids")
+}
+
+func generateID(p string) (string, error) {
+	if p == "" {
+		return generateRandomID()
+	}
+	h := sha1.New() //#nosec G401
+	if _, err := io.WriteString(h, p); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(h.Sum(nil)), nil
+}
+
+func generateRandomID() (string, error) {
+	h := sha1.New() //#nosec G401
+	if _, err := io.WriteString(h, xid.New().String()); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(h.Sum(nil)), nil
+}
+
+func reversePath(p string) []string {
+	return lo.Reverse(strings.Split(filepath.ToSlash(p), "/"))
+}
diff --git a/id_test.go b/id_test.go
index 709914f1..6f71d5b8 100644
--- a/id_test.go
+++ b/id_test.go
@@ -12,6 +12,50 @@ import (
 	"github.com/samber/lo"
 )
 
+func TestGenerateIDsUsingPath(t *testing.T) {
+	tests := []struct {
+		paths            []string
+		seedReversePaths []string
+	}{
+		{
+			[]string{"a.yml", "b.yml", "c.yml"},
+			[]string{"a.yml", "b.yml", "c.yml"},
+		},
+		{
+			[]string{"path/to/a.yml", "path/to/b.yml", "path/to/c.yml"},
+			[]string{"a.yml", "b.yml", "c.yml"},
+		},
+		{
+			[]string{"path/to/bb/a.yml", "path/to/aa/a.yml"},
+			[]string{"a.yml/bb", "a.yml/aa"},
+		},
+		{
+			[]string{"path/to/bb/a.yml", "../../path/to/aa/a.yml"},
+			[]string{"a.yml/bb", "a.yml/aa"},
+		},
+	}
+	for _, tt := range tests {
+		ops := []*operator{}
+		for _, p := range tt.paths {
+			ops = append(ops, &operator{
+				bookPath: p,
+			})
+		}
+		if err := generateIDsUsingPath(ops); err != nil {
+			t.Fatal(err)
+		}
+		for i, o := range ops {
+			want, err := generateID(tt.seedReversePaths[i])
+			if err != nil {
+				t.Fatal(err)
+			}
+			if o.id != want {
+				t.Errorf("want %s, got %s", want, o.id)
+			}
+		}
+	}
+}
+
 func BenchmarkReversePath(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		p := "/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z"
diff --git a/operator.go b/operator.go
index 3032864c..dead3749 100644
--- a/operator.go
+++ b/operator.go
@@ -20,7 +20,6 @@ import (
 	"github.com/goccy/go-json"
 	"github.com/k1LoW/concgroup"
 	"github.com/k1LoW/stopw"
-	"github.com/rs/xid"
 	"github.com/ryo-yamaoka/otchkiss"
 	"go.uber.org/multierr"
 )
@@ -412,9 +411,12 @@ func New(opts ...Option) (*operator, error) {
 	if err := bk.applyOptions(opts...); err != nil {
 		return nil, err
 	}
-
+	id, err := generateID(bk.path)
+	if err != nil {
+		return nil, err
+	}
 	o := &operator{
-		id:          generateRunbookID(),
+		id:          id,
 		httpRunners: map[string]*httpRunner{},
 		dbRunners:   map[string]*dbRunner{},
 		grpcRunners: map[string]*grpcRunner{},
@@ -1144,6 +1146,7 @@ func Load(pathp string, opts ...Option) (*operators, error) {
 	}
 	skipPaths := []string{}
 	om := map[string]*operator{}
+	opss := []*operator{}
 	for _, b := range books {
 		o, err := New(append([]Option{b}, opts...)...)
 		if err != nil {
@@ -1157,6 +1160,11 @@ func Load(pathp string, opts ...Option) (*operators, error) {
 			}
 		}
 		om[o.bookPath] = o
+		opss = append(opss, o)
+	}
+
+	if err := generateIDsUsingPath(opss); err != nil {
+		return nil, err
 	}
 
 	for p, o := range om {
@@ -1356,6 +1364,9 @@ func copyOperators(ops []*operator, opts []Option) ([]*operator, error) {
 		}
 		c = append(c, oo)
 	}
+	if err := generateIDsUsingPath(c); err != nil {
+		return nil, err
+	}
 	return c, nil
 }
 
@@ -1408,10 +1419,6 @@ func pop(s map[string]any) (string, any, bool) {
 	return "", nil, false
 }
 
-func generateRunbookID() string {
-	return xid.New().String()
-}
-
 func contains(s []string, e string) bool {
 	for _, v := range s {
 		if e == v {