diff --git a/khaosz/trainer/__init__.py b/khaosz/trainer/__init__.py
index 2954dbb..39470f0 100644
--- a/khaosz/trainer/__init__.py
+++ b/khaosz/trainer/__init__.py
@@ -1,4 +1,4 @@
-from khaosz.trainer.dataset import DatasetLoader
+from khaosz.trainer.data_util import DatasetLoader
 from khaosz.trainer.trainer import Trainer
 from khaosz.trainer.strategy import (
     TrainConfig, 
@@ -7,7 +7,7 @@ from khaosz.trainer.strategy import (
     StrategyFactory,
     SchedulerFactory
 )
-from khaosz.trainer.callback import (
+from khaosz.trainer.trainer_callback import (
     ProgressBarCallback,
     CheckpointCallback,
     TrainerCallback,
diff --git a/khaosz/trainer/dataset.py b/khaosz/trainer/data_util.py
similarity index 85%
rename from khaosz/trainer/dataset.py
rename to khaosz/trainer/data_util.py
index 3cf466e..ed19708 100644
--- a/khaosz/trainer/dataset.py
+++ b/khaosz/trainer/data_util.py
@@ -3,7 +3,7 @@ import bisect
 import pickle as pkl
 from abc import ABC, abstractmethod
 from torch import Tensor
-from torch.utils.data import Dataset
+from torch.utils.data import Dataset, Sampler
 from typing import Callable, List, Dict, Literal, Union
 
 MutiSeg = Dict[str, List[Tensor]]
@@ -264,4 +264,58 @@ class DatasetLoader:
         dataset = dataset_router[train_type](max_len, device)
         dataset.load(load_path)
         
-        return dataset
\ No newline at end of file
+        return dataset
+    
+
+class RandomSampler(Sampler[int]):
+    def __init__(self, data_source, generator=None, seed=42):
+        self.data_source = data_source
+        self.seed = seed
+        self.epoch = 0
+        self.current_index = 0
+        self._indices = None
+        
+        if generator is None:
+            self.generator = torch.Generator()
+            self.generator.manual_seed(seed)
+        else:
+            self.generator = generator
+    
+    def _generate_indices(self):
+        n = len(self.data_source)
+        self._indices = torch.randperm(n, generator=self.generator).tolist()
+    
+    def __iter__(self):
+        n = len(self.data_source)
+        
+        if self._indices is None:
+            self._generate_indices()
+        
+        for i in range(self.current_index, n):
+            yield self._indices[i]
+        
+        self.epoch += 1
+        self.current_index = 0
+        self._indices = None
+    
+    def __len__(self):
+        return len(self.data_source) - self.current_index
+    
+    def state_dict(self):
+        return {
+            'epoch': self.epoch,
+            'current_index': self.current_index,
+            'seed': self.seed,
+            'generator_state': self.generator.get_state() if self.generator else None,
+            'indices': self._indices
+        }
+    
+    def load_state_dict(self, state_dict):
+        self.epoch = state_dict['epoch']
+        self.current_index = state_dict['current_index']
+        self.seed = state_dict['seed']
+        
+        if self.generator and state_dict['generator_state'] is not None:
+            self.generator.set_state(state_dict['generator_state'])
+        
+        self._indices = state_dict['indices']
\ No newline at end of file
diff --git a/khaosz/trainer/trainer.py b/khaosz/trainer/trainer.py
index f374a65..6f8a46f 100644
--- a/khaosz/trainer/trainer.py
+++ b/khaosz/trainer/trainer.py
@@ -1,11 +1,12 @@
 import torch
 import itertools
 from typing import Optional, List
-from torch.utils.data import DataLoader, RandomSampler
+from torch.utils.data import DataLoader
 
 from khaosz.core import ModelParameter, Checkpoint
+from khaosz.trainer.data_util import RandomSampler
 from khaosz.trainer.strategy import TrainConfig, ScheduleConfig
-from khaosz.trainer.callback import (
+from khaosz.trainer.trainer_callback import (
     TrainerCallback, 
     ProgressBarCallback, 
     CheckpointCallback, 
@@ -42,7 +43,11 @@ class Trainer:
     def _create_dataloader(self, start_index: int = 0) -> DataLoader:
         seed = self.train_config.random_seed
         generator = torch.Generator().manual_seed(seed)
-        sampler = RandomSampler(self.train_config.dataset, generator=generator)
+        sampler = RandomSampler(
+            self.train_config.dataset, 
+            generator=generator,
+            seed=seed
+        )
         dataloader = DataLoader(
             self.train_config.dataset, 
             batch_size=self.train_config.batch_size, 
diff --git a/khaosz/trainer/callback.py b/khaosz/trainer/trainer_callback.py
similarity index 100%
rename from khaosz/trainer/callback.py
rename to khaosz/trainer/trainer_callback.py