diff --git a/vnpy/gateway/bitfinex/bitfinex_gateway.py b/vnpy/gateway/bitfinex/bitfinex_gateway.py
index c418813b..bcaab464 100644
--- a/vnpy/gateway/bitfinex/bitfinex_gateway.py
+++ b/vnpy/gateway/bitfinex/bitfinex_gateway.py
@@ -212,6 +212,7 @@ class BitfinexRestApi(RestClient):
                 product=Product.SPOT,
                 size=1,
                 pricetick=1 / pow(10, d["price_precision"]),
+                min_volume=float(d["minimum_order_size"]),
                 gateway_name=self.gateway_name,
             )
             self.gateway.on_contract(contract)
diff --git a/vnpy/gateway/huobi/huobi_gateway.py b/vnpy/gateway/huobi/huobi_gateway.py
index c2bb2a5c..79de4023 100644
--- a/vnpy/gateway/huobi/huobi_gateway.py
+++ b/vnpy/gateway/huobi/huobi_gateway.py
@@ -374,14 +374,15 @@ class HuobiRestApi(RestClient):
             quote_currency = d["quote-currency"]
             name = f"{base_currency.upper()}/{quote_currency.upper()}"
             pricetick = 1 / pow(10, d["price-precision"])
-            size = 1 / pow(10, d["amount-precision"])
-
+            min_volume = 1 / pow(10, d["amount-precision"])
+            
             contract = ContractData(
                 symbol=d["symbol"],
                 exchange=Exchange.HUOBI,
                 name=name,
                 pricetick=pricetick,
-                size=size,
+                size=1,
+                min_volume=min_volume,
                 product=Product.SPOT,
                 gateway_name=self.gateway_name,
             )
diff --git a/vnpy/gateway/okex/okex_gateway.py b/vnpy/gateway/okex/okex_gateway.py
index e959430e..184c6452 100644
--- a/vnpy/gateway/okex/okex_gateway.py
+++ b/vnpy/gateway/okex/okex_gateway.py
@@ -316,6 +316,7 @@ class OkexRestApi(RestClient):
                 product=Product.SPOT,
                 size=1,
                 pricetick=float(instrument_data["tick_size"]),
+                min_volume=float(instrument_data["min_size"]),
                 gateway_name=self.gateway_name
             )
             self.gateway.on_contract(contract)
diff --git a/vnpy/trader/object.py b/vnpy/trader/object.py
index b7ecd02e..734093cb 100644
--- a/vnpy/trader/object.py
+++ b/vnpy/trader/object.py
@@ -233,6 +233,7 @@ class ContractData(BaseData):
     size: int
     pricetick: float
 
+    min_volume: float = 1           # minimum trading volume of the contract
     stop_supported: bool = False    # whether server supports stop order
     net_position: bool = False      # whether gateway uses net position volume
 
diff --git a/vnpy/trader/ui/widget.py b/vnpy/trader/ui/widget.py
index e40da3c1..fa745825 100644
--- a/vnpy/trader/ui/widget.py
+++ b/vnpy/trader/ui/widget.py
@@ -550,11 +550,11 @@ class ConnectDialog(QtWidgets.QDialog):
             else:
                 field_value = field_type(widget.text())
             setting[field_name] = field_value
-        
+
         save_json(self.filename, setting)
-        
+
         self.main_engine.connect(setting, self.gateway_name)
-        
+
         self.accept()
 
 
@@ -893,6 +893,7 @@ class ContractManager(QtWidgets.QWidget):
         "product": "合约分类",
         "size": "合约乘数",
         "pricetick": "价格跳动",
+        "min_volume": "最小委托量",
         "gateway_name": "交易接口",
     }