diff --git a/docs/en/setup/service-agent/java-agent/README.md b/docs/en/setup/service-agent/java-agent/README.md
index d390e87b0..4d7e556ff 100755
--- a/docs/en/setup/service-agent/java-agent/README.md
+++ b/docs/en/setup/service-agent/java-agent/README.md
@@ -68,7 +68,7 @@ property key | Description | Default |
 `agent.service_name` | Application(5.x)/Service(6.x) code is showed in sky-walking-ui. Suggestion: set a unique name for each service, service instance nodes share the same code | `Your_ApplicationName` |
 `agent.sample_n_per_3_secs`|Negative or zero means off, by default.SAMPLE_N_PER_3_SECS means sampling N TraceSegment in 3 seconds tops.|Not set|
 `agent.authentication`|Authentication active is based on backend setting, see application.yml for more details.For most scenarios, this needs backend extensions, only basic match auth provided in default implementation.|Not set|
-`agent.span_limit_per_segment`|The max number of spans in a single segment. Through this config item, skywalking keep your application memory cost estimated.|Not set |
+`agent.span_limit_per_segment`|The max number of spans in a single segment. Through this config item, skywalking keep your application memory cost estimated.|300 |
 `agent.ignore_suffix`|If the operation name of the first span is included in this set, this segment should be ignored.|Not set|
 `agent.is_open_debugging_class`|If true, skywalking agent will save all instrumented classes files in `/debugging` folder.Skywalking team may ask for these files in order to resolve compatible problem.|Not set|
 `agent.active_v2_header`|Active V2 header in default.|`true`|