Facing pressure on net interest margins after two rounds of interest rate cuts in 2012, AgBank's net profit rose 19 percent to $23.36 billion last year, compared to growth of 28.5 percent in 2011. BOC's net profit grew 12.2 percent to $22.4 billion after rising 19 percent in the year before. China Construction Bank (CCB), meanwhile, saw net profit rise 14 percent, better than expected.
Earnings from the Industrial and Commercial Bank of China (ICBC), the world's biggest bank by market value, is expected on Wednesday.
While the results so far still show double digit growth, the banks themselves admit that growth is slowing, hit by the cooling of China's economy, which has impacted margins.
China Big 5 Banks' 2012 Profit Seen Up 12%
But Timothy Wong, managing director and regional head of DBS Group Research points out that recent macroeconomic data have shown that China's economy is improving and this should bode well for the banks. He says the banks' share price already reflect the latest earnings. So far this year, Hong Kong listed shares of ICBC and AgBank are down about 1 percent, while CCB has gained nearly 3 percent and BOC is up 4 percent.
"I think what's priced in is that the worst is probably over. We do see pressure on the net interest margin side, on margins, but I think the sense is that non-performing loans are not going to get a lot worse in 2013," Wong said.
Fears that non-performing loans at the country's banks will spike amid the slowdown have led several analysts to question the reliability of the earnings announced by banks.
Both BOC and AgBank have reported that their non-performing loan ratios remained largely unchanged at 0.95 percent and 1.33 percent respectively at the end of 2012.
But Donald Straszheim, senior managing director, International Strategy & Investment said "It's hard to believe those 1 percent non-performing loan rates that they [the banks] put out."
However, he does add that China's still got "pretty good" economic growth, which could minimize the impact of the bad loans.
"On the other hand, they still got pretty good nominal income growth, and a lot of those loans are getting smaller and smaller, " Straszheim said.
-By CNBC.com's Rajeshni Naidu-Ghelani; Follow her on Twitter