For the full year of 2021, net revenue was RMB20.0 billion (US$3.1 billion), representing a 9% increase from 2020.
Accommodation reservation revenue for the fourth quarter of 2021 was RMB1.9 billion (US$301 million), representing a 14% decrease from the same period in 2020, and a 13% decrease from the previous quarter, primarily due to the re-emergence of COVID-19 infections in certain regions in China.
For the full year of 2021, accommodation reservation revenue was RMB8.1 billion (US$1.3 billion), representing a 14% increase from 2020. The accommodation reservation revenue accounted for 41% of the total revenue in 2021 and 39% of the total revenue in 2020.
Transportation ticketing revenue for the fourth quarter of 2021 was RMB1.5 billion (US$238 million), representing a 11% decrease from the same period in 2020, and a 17% decrease from the previous quarter, primarily due to the re-emergence of COVID-19 infections in certain regions in China.
For the full year of 2021, transportation ticketing revenue was RMB6.9 billion (US$1.1 billion), representing a 3% decrease from 2020. The transportation ticketing revenue accounted for 34% of the total revenue in 2021 and 39% of the total revenue in 2020.
Packaged-tour revenue for the fourth quarter of 2021 was RMB177 million (US$28 million), representing a 32% decrease from the same period in 2020 and a 55% decrease from the previous quarter, primarily due to the re-emergence of COVID-19 infections in certain regions in China.
For the full year of 2021, packaged-tour revenue was RMB1.1 billion (US$173 million), representing an 11% decrease from 2020. The packaged-tour revenue accounted for 6% of the total revenue in 2021 and 7% of the total revenue in 2020.
Corporate travel revenue for the fourth quarter of 2021 was RMB367 million (US$58 million), representing a 20% increase from the same period in 2020 and a 9% increase from the previous quarter, primarily driven by expansion in corporate customer base and an optimized product mix.
For the full year of 2021, corporate travel revenue was RMB1.3 billion (US$211 million), representing a 54% increase from 2020. The corporate travel revenue accounted for 7% of the total revenue in 2021 and 5% of the total revenue in 2020.
Cost of revenue for the fourth quarter of 2021 increased by 23% to RMB1.1 billion (US$176 million) from the same period in 2020, primarily due to an increase in compensation to customer service center personnel. Cost of revenue decreased by 9% compared to the previous quarter. Cost of revenue as a percentage of net revenue was 24% for the fourth quarter of 2021.
For the full year of 2021, cost of revenue increased by 14% to RMB4.6 billion (US$721 million) from 2020, amounting to 23% as a percentage of net revenue.