diff --git a/AssetManager.Infrastructure/Services/YahooMarketService.cs b/AssetManager.Infrastructure/Services/YahooMarketService.cs
index b688299..c07d991 100644
--- a/AssetManager.Infrastructure/Services/YahooMarketService.cs
+++ b/AssetManager.Infrastructure/Services/YahooMarketService.cs
@@ -40,11 +40,27 @@ public class YahooMarketService : IYahooMarketService
             .Build();
     }
 
+    /// <summary>
+    /// 转换股票代码为 Yahoo Finance 格式
+    /// <para>BRK.B → BRK-B（伯克希尔B类股）</para>
+    /// <para>BRK.A → BRK-A（伯克希尔A类股）</para>
+    /// </summary>
+    private string ConvertToYahooSymbol(string symbol)
+    {
+        if (string.IsNullOrEmpty(symbol))
+            return symbol;
+        
+        // Yahoo Finance 用连字符表示类别股，而非点号
+        // BRK.B → BRK-B, BRK.A → BRK-A
+        return symbol.ToUpper().Replace(".", "-");
+    }
+
     public async Task<MarketPriceResponse> GetStockPriceAsync(string symbol)
     {
-        _logger.LogInformation("Yahoo获取股票价格: {Symbol}", symbol);
+        var yahooSymbol = ConvertToYahooSymbol(symbol);
+        _logger.LogInformation("Yahoo获取股票价格: {Symbol} -> {YahooSymbol}", symbol, yahooSymbol);
         
-        Snapshot? snapshot = await _yahooQuotes.GetSnapshotAsync(symbol);
+        Snapshot? snapshot = await _yahooQuotes.GetSnapshotAsync(yahooSymbol);
         if (snapshot is null)
             throw new InvalidOperationException($"Yahoo未知标的: {symbol}");
         
@@ -61,7 +77,7 @@ public class YahooMarketService : IYahooMarketService
 
         return new MarketPriceResponse
         {
-            Symbol = symbol,
+            Symbol = symbol, // 返回原始代码
             Price = price,
             PreviousClose = previousClose,
             Timestamp = DateTime.UtcNow,
@@ -71,9 +87,10 @@ public class YahooMarketService : IYahooMarketService
 
     public async Task<List<MarketDataResponse>> GetStockHistoricalDataAsync(string symbol, string timeframe, int limit)
     {
-        _logger.LogInformation("Yahoo获取历史数据: {Symbol}, {Timeframe}, {Limit}", symbol, timeframe, limit);
+        var yahooSymbol = ConvertToYahooSymbol(symbol);
+        _logger.LogInformation("Yahoo获取历史数据: {Symbol} -> {YahooSymbol}, {Timeframe}, {Limit}", symbol, yahooSymbol, timeframe, limit);
         
-        Result<History> result = await _yahooQuotes.GetHistoryAsync(symbol);
+        Result<History> result = await _yahooQuotes.GetHistoryAsync(yahooSymbol);
         if (result.Value == null)
             throw new InvalidOperationException($"Yahoo获取历史数据失败，标的: {symbol}");
         
@@ -86,7 +103,7 @@ public class YahooMarketService : IYahooMarketService
         {
             marketDataList.Add(new MarketDataResponse
             {
-                Symbol = symbol,
+                Symbol = symbol, // 返回原始代码
                 Timestamp = tick.Date.ToDateTimeUtc(),
                 Open = (decimal)tick.Open,
                 High = (decimal)tick.High,