Hello guys, green hand i am. I'm using instruments, and it did a great help to me so far, but I'm confused now 'cause it report a memory leak to me while its leaked block history shows me that the ref count of that memory had finally become 0. What does it mean? It's really embarrassing that I couldn't post a image here... so I have to describe it in text. Hope it would be clear enough for you: Event Type || RefCt || Responsible Library || Responsible Caller Malloc         || 1        || MyWeather              || +[ForecastData parseSingleForecastWithXMLElement:] Autorelease||           || MyWeather              || +[ForecastData parseSingleForecastWithXMLElement:] Retain         || 2        || MyWeather              || +[ForecastData parseWithData:] Release      || 1        || Foundation              || +[NSAutoreleasePool drain:] Retain         || 2        || Foundation              || +[NSThread initWithTarget:selector:object:] Release      || 1        || Foundation              || +[NSString compare:options:] Release      || 0        || MyWeather              || +[RootViewController dealloc] Any help will be appreciated~