diff --git a/library/train_util.py b/library/train_util.py
index 8c6e3437..a8ee260c 100644
--- a/library/train_util.py
+++ b/library/train_util.py
@@ -1883,7 +1883,7 @@ def add_optimizer_arguments(parser: argparse.ArgumentParser):
         "--optimizer_type",
         type=str,
         default="",
-        help="Optimizer to use / オプティマイザの種類: AdamW (default), AdamW8bit, Lion, SGDNesterov, SGDNesterov8bit, DAdaptation, AdaFactor",
+        help="Optimizer to use / オプティマイザの種類: AdamW (default), AdamW8bit, Lion, Lion8bit,SGDNesterov, SGDNesterov8bit, DAdaptation, AdaFactor",
     )
 
     # backward compatibility
@@ -2448,7 +2448,7 @@ def resume_from_local_or_hf_if_specified(accelerator, args):
 
 
 def get_optimizer(args, trainable_params):
-    # "Optimizer to use: AdamW, AdamW8bit, Lion, SGDNesterov, SGDNesterov8bit, DAdaptation, Adafactor"
+    # "Optimizer to use: AdamW, AdamW8bit, Lion, Lion8bit, SGDNesterov, SGDNesterov8bit, DAdaptation, Adafactor"
 
     optimizer_type = args.optimizer_type
     if args.use_8bit_adam:
@@ -2525,6 +2525,15 @@ def get_optimizer(args, trainable_params):
         print(f"use Lion optimizer | {optimizer_kwargs}")
         optimizer_class = lion_pytorch.Lion
         optimizer = optimizer_class(trainable_params, lr=lr, **optimizer_kwargs)
+        
+    elif optimizer_type == "Lion8bit".lower():
+        try:
+            import bitsandbytes as bnb
+        except ImportError:
+            raise ImportError("No bitsand bytes / bitsandbytesがインストールされていないようです")
+        print(f"use 8-bit Lion optimizer | {optimizer_kwargs}")
+        optimizer_class = bnb.optim.Lion8bit
+        optimizer = optimizer_class(trainable_params, lr=lr, **optimizer_kwargs)
 
     elif optimizer_type == "SGDNesterov".lower():
         print(f"use SGD with Nesterov optimizer | {optimizer_kwargs}")
diff --git a/train_README-ja.md b/train_README-ja.md
index fd66458a..a155febd 100644
--- a/train_README-ja.md
+++ b/train_README-ja.md
@@ -563,6 +563,7 @@ masterpiece, best quality, 1boy, in business suit, standing at street, looking b
     - 過去のバージョンの--use_8bit_adam指定時と同じ
     - Lion : https://github.com/lucidrains/lion-pytorch
     - 過去のバージョンの--use_lion_optimizer指定時と同じ
+    - Lion8bit : 引数は同上
     - SGDNesterov : [torch.optim.SGD](https://pytorch.org/docs/stable/generated/torch.optim.SGD.html), nesterov=True
     - SGDNesterov8bit : 引数は同上
     - DAdaptation : https://github.com/facebookresearch/dadaptation