If thisform.oMsComm1.input does indeed have the data, you must do something with it. I normally create a form property called 'inbuffer'. Then in the OnComm event, just do:

THISFORM.inbuffer = THISFORM.inbuffer + thisform.oMsComm1.input

adds the input to the buffer. Now process the buffer elsewhere.

>I found the onComm event does fire when my comm port received data.
>
>But when I try receive data by manually (thisform.oMsComm1.input), I found the data is there. Why??
>
>How can I configure it to make it working properly????
>
>TIA.