diff --git a/level/chunk.go b/level/chunk.go
index c9edef5..a684fe6 100644
--- a/level/chunk.go
+++ b/level/chunk.go
@@ -13,14 +13,14 @@ import (
 	"github.com/Tnze/go-mc/save"
 )
 
-type ChunkPos struct{ X, Z int }
+type ChunkPos [2]int32
 
 func (c ChunkPos) WriteTo(w io.Writer) (n int64, err error) {
-	n, err = pk.Int(c.X).WriteTo(w)
+	n, err = pk.Int(c[0]).WriteTo(w)
 	if err != nil {
 		return
 	}
-	n1, err := pk.Int(c.Z).WriteTo(w)
+	n1, err := pk.Int(c[1]).WriteTo(w)
 	return n + n1, err
 }
 
@@ -33,7 +33,7 @@ func (c *ChunkPos) ReadFrom(r io.Reader) (n int64, err error) {
 	if n1, err = z.ReadFrom(r); err != nil {
 		return n + n1, err
 	}
-	*c = ChunkPos{int(x), int(z)}
+	*c = ChunkPos{int32(x), int32(z)}
 	return n + n1, nil
 }
 
@@ -41,6 +41,7 @@ type Chunk struct {
 	Sections    []Section
 	HeightMaps  HeightMaps
 	BlockEntity []BlockEntity
+	Status      ChunkStatus
 }
 
 func EmptyChunk(secs int) *Chunk {
@@ -57,6 +58,7 @@ func EmptyChunk(secs int) *Chunk {
 		HeightMaps: HeightMaps{
 			MotionBlocking: NewBitStorage(bits.Len(uint(secs)*16), 16*16, nil),
 		},
+		Status: StatusEmpty,
 	}
 }
 
@@ -220,6 +222,7 @@ func ChunkFromSave(c *save.Chunk) (*Chunk, error) {
 			OceanFloor:             NewBitStorage(bitsForHeight, 16*16, oceanFloor),
 			WorldSurface:           NewBitStorage(bitsForHeight, 16*16, worldSurface),
 		},
+		Status: ChunkStatus(c.Status),
 	}, nil
 }
 
@@ -278,7 +281,8 @@ func ChunkToSave(c *Chunk, dst *save.Chunk) (err error) {
 		s.BlockLight = v.BlockLight
 	}
 	dst.Sections = sections
-	//dst.Heightmaps.MotionBlocking = c.HeightMaps.MotionBlocking.Raw()
+	dst.Heightmaps.MotionBlocking = c.HeightMaps.MotionBlocking.Raw()
+	dst.Status = string(c.Status)
 	return
 }
 
diff --git a/level/chunkstatus.go b/level/chunkstatus.go
new file mode 100644
index 0000000..c8a1c96
--- /dev/null
+++ b/level/chunkstatus.go
@@ -0,0 +1,19 @@
+package level
+
+type ChunkStatus string
+
+const (
+	StatusEmpty               ChunkStatus = "empty"
+	StatusStructureStarts     ChunkStatus = "structure_starts"
+	StatusStructureReferences ChunkStatus = "structure_references"
+	StatusBiomes              ChunkStatus = "biomes"
+	StatusNoise               ChunkStatus = "noise"
+	StatusSurface             ChunkStatus = "surface"
+	StatusCarvers             ChunkStatus = "carvers"
+	StatusLiquidCarvers       ChunkStatus = "liquid_carvers"
+	StatusFeatures            ChunkStatus = "features"
+	StatusLight               ChunkStatus = "light"
+	StatusSpawn               ChunkStatus = "spawn"
+	StatusHeightmaps          ChunkStatus = "heightmaps"
+	StatusFull                ChunkStatus = "full"
+)
diff --git a/save/region/mca.go b/save/region/mca.go
index 9ded58c..4a5a6d1 100644
--- a/save/region/mca.go
+++ b/save/region/mca.go
@@ -28,6 +28,12 @@ func In(cx, cz int) (int, int) {
 	return cx & 31, cz & 31
 }
 
+// At calculate the region's coordinates where the chunk in
+// 计算chunk在哪一个region中
+func At(cx, cz int) (int, int) {
+	return cx >> 5, cz >> 5
+}
+
 // Open a .mca file and read the head.
 // Close the Region after used.
 func Open(name string) (r *Region, err error) {
diff --git a/server/clientinfo/clientinfo.go b/server/clientinfo/clientinfo.go
deleted file mode 100644
index cb497b9..0000000
--- a/server/clientinfo/clientinfo.go
+++ /dev/null
@@ -1,89 +0,0 @@
-package clientinfo
-
-import (
-	"context"
-	"github.com/Tnze/go-mc/server/ecs"
-
-	"github.com/Tnze/go-mc/data/packetid"
-	pk "github.com/Tnze/go-mc/net/packet"
-	"github.com/Tnze/go-mc/server"
-)
-
-type ClientInformation struct{}
-
-type Info struct {
-	Locale              string
-	ViewDistance        int
-	ChatMode            byte
-	ChatColors          bool
-	DisplayedSkinParts  byte
-	MainHand            byte // 0: Left, 1: Right.
-	EnableTextFiltering bool
-	AllowServerListings bool
-}
-
-func (c *ClientInformation) Init(g *server.Game) {
-	infos := ecs.GetComponent[Info](g.World)
-	type updateData struct {
-		eid  ecs.Index
-		info Info
-	}
-	updateChan := make(chan updateData)
-	g.Add(ecs.FuncSystem(func() {
-		for {
-			select {
-			case info := <-updateChan:
-				infos.SetValue(info.eid, info.info)
-			default:
-				return
-			}
-		}
-	}), "go-mc:ClientInfoSystem", nil)
-	g.AddHandler(&server.PacketHandler{
-		ID: packetid.ServerboundClientInformation,
-		F: func(client *server.Client, player *server.Player, p server.Packet758) error {
-			var (
-				Locale              pk.String
-				ViewDistance        pk.Byte
-				ChatMode            pk.VarInt
-				ChatColors          pk.Boolean
-				DisplayedSkinParts  pk.UnsignedByte
-				MainHand            pk.VarInt
-				EnableTextFiltering pk.Boolean
-				AllowServerListings pk.Boolean
-			)
-			err := pk.Packet(p).Scan(
-				&Locale,
-				&ViewDistance,
-				&ChatMode,
-				&ChatColors,
-				&DisplayedSkinParts,
-				&MainHand,
-				&EnableTextFiltering,
-				&AllowServerListings,
-			)
-			if err != nil {
-				return err
-			}
-
-			updateChan <- updateData{
-				eid: client.Index,
-				info: Info{
-					Locale:              string(Locale),
-					ViewDistance:        int(ViewDistance),
-					ChatMode:            byte(ChatMode),
-					ChatColors:          bool(ChatColors),
-					DisplayedSkinParts:  byte(DisplayedSkinParts),
-					MainHand:            byte(MainHand),
-					EnableTextFiltering: bool(EnableTextFiltering),
-					AllowServerListings: bool(AllowServerListings),
-				},
-			}
-			return nil
-		},
-	})
-}
-
-func (c *ClientInformation) Run(ctx context.Context)                                               {}
-func (c *ClientInformation) ClientJoin(client *server.Client, player *server.Player)               {}
-func (c *ClientInformation) ClientLeft(client *server.Client, player *server.Player, reason error) {}