diff --git a/src/main/java/codesquad/fineants/domain/stock/domain/entity/Stock.java b/src/main/java/codesquad/fineants/domain/stock/domain/entity/Stock.java
index 52f6bb3c..149ecf50 100644
--- a/src/main/java/codesquad/fineants/domain/stock/domain/entity/Stock.java
+++ b/src/main/java/codesquad/fineants/domain/stock/domain/entity/Stock.java
@@ -16,6 +16,7 @@
 import codesquad.fineants.domain.kis.repository.CurrentPriceRepository;
 import codesquad.fineants.domain.purchasehistory.domain.entity.PurchaseHistory;
 import codesquad.fineants.domain.stock.converter.MarketConverter;
+import codesquad.fineants.infra.s3.service.AmazonS3StockService;
 import jakarta.persistence.Convert;
 import jakarta.persistence.Entity;
 import jakarta.persistence.FetchType;
@@ -220,7 +221,7 @@ public List<StockDividend> getStockDividendNotInRange(LocalDate from, LocalDate
 	}
 
 	public String toCsvLineString() {
-		return String.join(",",
+		return String.join(AmazonS3StockService.CSV_SEPARATOR,
 			stockCode,
 			tickerSymbol,
 			companyName,
diff --git a/src/main/java/codesquad/fineants/domain/stock/service/StockService.java b/src/main/java/codesquad/fineants/domain/stock/service/StockService.java
index 96ff619c..e6b825f0 100644
--- a/src/main/java/codesquad/fineants/domain/stock/service/StockService.java
+++ b/src/main/java/codesquad/fineants/domain/stock/service/StockService.java
@@ -61,14 +61,15 @@ public StockResponse getDetailedStock(String tickerSymbol) {
 	@Scheduled(cron = "0 0 8 * * ?") // 매일 오전 8시 (초, 분, 시간)
 	@Transactional
 	public void scheduledReloadStocks() {
-		StockReloadResponse response = stockAndDividendManager.reloadStocks();
-		log.info("refreshStocks response : {}", response);
-		amazonS3StockService.writeStocks(stockRepository.findAll());
-		amazonS3DividendService.writeDividends(stockDividendRepository.findAll());
+		reloadStocks();
 	}
 
 	@Transactional
 	public StockReloadResponse reloadStocks() {
-		return stockAndDividendManager.reloadStocks();
+		StockReloadResponse response = stockAndDividendManager.reloadStocks();
+		log.info("refreshStocks response : {}", response);
+		amazonS3StockService.writeStocks(stockRepository.findAll());
+		amazonS3DividendService.writeDividends(stockDividendRepository.findAll());
+		return response;
 	}
 }
diff --git a/src/main/java/codesquad/fineants/infra/s3/service/AmazonS3StockService.java b/src/main/java/codesquad/fineants/infra/s3/service/AmazonS3StockService.java
index 87b841d4..de309879 100644
--- a/src/main/java/codesquad/fineants/infra/s3/service/AmazonS3StockService.java
+++ b/src/main/java/codesquad/fineants/infra/s3/service/AmazonS3StockService.java
@@ -33,7 +33,7 @@
 @Slf4j
 public class AmazonS3StockService {
 
-	public static final String CSV_SEPARATOR = ",";
+	public static final String CSV_SEPARATOR = ":";
 
 	private final AmazonS3 amazonS3;
 	@Value("${aws.s3.bucket}")
diff --git a/src/test/java/codesquad/fineants/domain/stock/domain/entity/StockTest.java b/src/test/java/codesquad/fineants/domain/stock/domain/entity/StockTest.java
new file mode 100644
index 00000000..80fc8337
--- /dev/null
+++ b/src/test/java/codesquad/fineants/domain/stock/domain/entity/StockTest.java
@@ -0,0 +1,21 @@
+package codesquad.fineants.domain.stock.domain.entity;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+class StockTest {
+
+	@DisplayName("csv에 저장하기 위해서 쉼표(,)로 구분한 한줄의 문자열로 변환한다")
+	@Test
+	void toCsvLineString() {
+		// given
+		Stock stock = Stock.of("000370", "한화손해보험보통주", "Hanwha General Insurance Co.,Ltd.", "KR7000370007", "보험",
+			Market.KOSPI);
+		// when
+		String result = stock.toCsvLineString();
+		// then
+		String expected = "KR7000370007:000370:한화손해보험보통주:Hanwha General Insurance Co.,Ltd.:KOSPI:보험";
+		Assertions.assertThat(result).isEqualTo(expected);
+	}
+}
diff --git a/src/test/java/codesquad/fineants/infra/s3/service/AmazonS3StockServiceTest.java b/src/test/java/codesquad/fineants/infra/s3/service/AmazonS3StockServiceTest.java
new file mode 100644
index 00000000..0157c56a
--- /dev/null
+++ b/src/test/java/codesquad/fineants/infra/s3/service/AmazonS3StockServiceTest.java
@@ -0,0 +1,37 @@
+package codesquad.fineants.infra.s3.service;
+
+import java.util.List;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import codesquad.fineants.AbstractContainerBaseTest;
+import codesquad.fineants.domain.stock.domain.entity.Market;
+import codesquad.fineants.domain.stock.domain.entity.Stock;
+
+class AmazonS3StockServiceTest extends AbstractContainerBaseTest {
+
+	@Autowired
+	private AmazonS3StockService amazonS3StockService;
+
+	@DisplayName("종목 정보를 csv 파일에 저장한다")
+	@Test
+	void writeStocks() {
+		// given
+		Stock stock = Stock.of("000370", "한화손해보험보통주", "Hanwha General Insurance Co.,Ltd.", "KR7000370007", "보험",
+			Market.KOSPI);
+		// when
+		amazonS3StockService.writeStocks(List.of(stock));
+		// then
+		Stock findStock = amazonS3StockService.fetchStocks().stream()
+			.findAny()
+			.orElseThrow();
+		Assertions.assertThat(findStock)
+			.extracting(Stock::getTickerSymbol, Stock::getCompanyName, Stock::getCompanyNameEng, Stock::getStockCode,
+				Stock::getSector, Stock::getMarket)
+			.containsExactly("000370", "한화손해보험보통주", "Hanwha General Insurance Co.,Ltd.", "KR7000370007", "보험",
+				Market.KOSPI);
+	}
+}